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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For the Quarterly Period Ended March 31, 2012

Commission File Number: 1-10777

Ambac Financial Group, Inc.

(Debtor-in-possession as of November 8, 2010)

(Exact name of Registrant as specified in its charter)

(212) 668-0340

(Registrant’s telephone number, including area code)

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definition of “large accelerated filer”, “accelerated filer”, and “smaller reporting company” in Rule 12b-2 of the Exchange Act): (Check one):

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of May 4, 2012, 302,431,515 shares of common stock, par value $0.01 per share, of the Registrant were outstanding.

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Ambac Financial Group, Inc. and Subsidiaries

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Part I Financial Information

AMBAC FINANCIAL GROUP, INC. AND SUBSIDIARIES

DEBTOR-IN-POSSESSION

Consolidated Balance Sheets

See accompanying Notes to Unaudited Consolidated Financial Statements.

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AMBAC FINANCIAL GROUP, INC. AND SUBSIDIARIES

DEBTOR-IN-POSSESSION

Consolidated Statements of Total Comprehensive Income (Unaudited)

See accompanying Notes to Unaudited Consolidated Financial Statements

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AMBAC FINANCIAL GROUP, INC. AND SUBSIDIARIES

DEBTOR-IN-POSSESSION

Consolidated Statements of Stockholders’ Equity (Unaudited)

See accompanying Notes to Unaudited Consolidated Financial Statements.

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AMBAC FINANCIAL GROUP, INC. AND SUBSIDIARIES

DEBTOR-IN-POSSESSION

Consolidated Statements of Cash Flows (Unaudited)

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Supplemental disclosure of noncash financing activities:

In March 2011, the Segregated Account of Ambac Assurance established pursuant to Wisc. Stat. §611.24(2) (the “Segregated Account”) to segregate certain segments of Ambac Assurance’s liabilities, issued surplus notes in connection with the commutation of two insurance policies with a par value of $3,000.

See accompanying Notes to Unaudited Consolidated Financial Statements.

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AMBAC FINANCIAL GROUP, INC. AND SUBSIDIARIES

DEBTOR-IN-POSSESSION

Notes to Unaudited Consolidated Financial Statements

(Dollar Amounts in Thousands, Except Share Amounts)

1. Background and Basis of Presentation

These unaudited consolidated financial statements and notes thereto should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s 2011 Annual Report on Form 10-K.

Ambac Financial Group, Inc. (“Ambac” or the “Company”), headquartered in New York City, is a holding company incorporated in the state of Delaware. Ambac was incorporated on April 29, 1991. On November 8, 2010 (the “Petition Date”), Ambac filed a voluntary petition for relief (the “Bankruptcy Filing”) under Chapter 11 of the United States Bankruptcy Code (“Bankruptcy Code”) in the United States Bankruptcy Court for the Southern District of New York (“Bankruptcy Court”). Ambac has continued to operate in the ordinary course of business as “debtor-in-possession” under the jurisdiction of the Bankruptcy Court and in accordance with the applicable provisions of the Bankruptcy Code and the orders of the Bankruptcy Court. The Company, as debtor and debtor-in-possession, filed a Fifth Amended Plan of Reorganization on March 12, 2012 (such Fifth Amended Plan of Reorganization, as it may be amended, the “Reorganization Plan”). The Bankruptcy Court entered an order confirming the Reorganization Plan on March 14, 2012. Under the Reorganization Plan, Ambac’s debt holders and other creditors will receive all of the equity in the reorganized company. Therefore, if the Reorganization Plan is consummated, our existing common stock will be cancelled and extinguished and the holders thereof would not be entitled to receive, and would not receive or retain any property or interest in property on account of such equity interests. Additionally, the Reorganization Plan sets forth the revised capital structure of a newly reorganized Ambac and provides for corporate governance subsequent to emergence from bankruptcy.

Ambac Assurance Corporation (“Ambac Assurance”) is Ambac’s principal operating subsidiary. Ambac Assurance is a financial guarantee insurer that provided financial guarantees and financial services to clients in both the public and private sectors around the world. In March 2010, Ambac Assurance established a segregated account pursuant to Wisc. Stat. §611.24(2) (the “Segregated Account”) to segregate certain segments of Ambac Assurance’s liabilities. The Office of the Commissioner of Insurance for the State of Wisconsin (“OCI” (which term shall be understood to refer to such office as regulator of Ambac Assurance and the Commissioner of Insurance for the State of Wisconsin as rehabilitator of the Segregated Account (the “Rehabilitator”), as the context requires)) commenced rehabilitation proceedings with respect to the Segregated Account (the “Segregated Account Rehabilitation Proceedings”) in order to permit the OCI to facilitate an orderly run-off and/or settlement of the liabilities allocated to the Segregated Account pursuant to the provisions of the Wisconsin Insurers Rehabilitation and Liquidation Act. The Rehabilitator is Theodore Nickel, the Commissioner of Insurance of the State of Wisconsin. Ambac Assurance is not, itself, in rehabilitation proceedings.

On October 8, 2010, the Rehabilitator filed a plan of rehabilitation for the Segregated Account (the “Segregated Account Rehabilitation Plan”) in the Circuit Court of Dane County, Wisconsin in which the Segregated Account Rehabilitation Proceedings are pending (the “Rehabilitation Court”). The Rehabilitation Court confirmed the Segregated Account Rehabilitation Plan on January 24, 2011. The confirmed Segregated Account Rehabilitation Plan also makes permanent the injunctions issued by the Rehabilitation Court on March 24, 2010.

The Segregated Account Rehabilitation Plan is not effective and is subject to modification. Pursuant to the injunctions issued by the Rehabilitation Court, claims on policies allocated to the Segregated Account have not been paid since the commencement of the Segregated Account Rehabilitation Proceedings. Net par exposure as of March 31, 2012 for policies allocated to the Segregated Account is $33,593,393. The Rehabilitator may seek to effectuate the current Segregated Account Rehabilitation Plan, modify such Plan or modify the injunctions issued by the Rehabilitation Court to allow for the payment of policy claims in such manner and at such times as the Rehabilitator determines to be in the best interest of policyholders. The deterioration of Ambac Assurance’s financial condition resulting from losses in its insured portfolio caused downgrades, and ultimately withdrawals of Ambac Assurance’s

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financial strength ratings from the independent rating agencies. These losses have prevented Ambac Assurance from being able to write new business. An inability to write new business has and will continue to negatively impact Ambac’s future operations and financial results. Ambac Assurance’s ability to pay dividends, and as a result Ambac’s liquidity, have been significantly restricted by the deterioration of Ambac Assurance’s financial condition, by the rehabilitation of the Segregated Account and by the terms of the Settlement Agreement entered into on June 7, 2010 by Ambac, Ambac Assurance, Ambac Credit Products, LLC (“ACP”) and counterparties to outstanding credit default swaps with ACP (the “Settlement Agreement”). Ambac Assurance is also restricted in its ability to pay dividends pursuant to the terms of its Auction Market Preferred Shares (“AMPS”), which state that dividends may not be paid on the common stock of Ambac Assurance unless all accrued and unpaid dividends on the AMPS for the then current dividend period have been paid, provided that dividends on the common stock may be made at all times for the purpose of, and only in such amounts as are necessary for enabling Ambac (i) to service its indebtedness for borrowed money as such payments become due or (ii) to pay its operating expenses. If dividends are paid on the common stock as provided in the prior sentence, dividends on the AMPS become cumulative until the date that all accumulated and unpaid dividends have been paid on the AMPS. Ambac Assurance has not paid dividends on AMPS since 2010. Based on the above described restrictions and circumstances, it is highly unlikely that Ambac Assurance will be able to make dividend payments to Ambac for the foreseeable future.

Chapter 11 Reorganization

The Reorganization Plan reflects a resolution of certain issues (the “Amended Plan Settlement”) among the Company, the statutory committee of creditors appointed by the United States Trustee on November 17, 2010 (the “Creditors’ Committee”), Ambac Assurance, the Segregated Account and OCI related to (i) the net operating loss carryforwards (“NOLs”) of the consolidated tax group of which the Company is the parent and Ambac Assurance is a member (the “Ambac Consolidated Group”), (ii) certain tax refunds received in respect thereof (the “Tax Refunds”) and (iii) the sharing of expenses between the Company and Ambac Assurance. The terms of the Amended Plan Settlement are memorialized in that certain Mediation Agreement dated September 21, 2011 (the “Mediation Agreement”) among such parties. In accordance with the Amended Plan Settlement, the Company shall retain ownership of Ambac Assurance, and except as otherwise approved by OCI, the Company shall use its best efforts to preserve the use of NOLs as contemplated by the Amended Plan Settlement.

Pursuant to the Amended Plan Settlement, (i) the Company, Ambac Assurance and certain affiliates entered into an amended and restated tax sharing agreement (the “Amended TSA”), (ii) the Company, Ambac Assurance and certain affiliates entered into an expense sharing and cost allocation agreement (the “Cost Allocation Agreement”) and (iii) the Company, Ambac Assurance, the Segregated Account and OCI entered into an amendment (the “Cooperation Agreement Amendment”), of that certain Cooperation Agreement, dated as of March 24, 2010, by and between the Segregated Account and Ambac Assurance (the “Cooperation Agreement”).

The Amended TSA replaces, supersedes and nullifies in its entirety the existing tax sharing agreement among the Company and its affiliates. The Amended TSA addresses certain issues including, but not limited to, the allocation and use of NOLs by the Company, Ambac Assurance and their respective subsidiaries.

The Cost Allocation Agreement provides for the allocation of costs and expenses among the Company, Ambac Assurance and certain affiliates. The Mediation Agreement also provides for sharing by the Company and Ambac Assurance of the expenses incurred since November 1, 2010 in connection with the litigation with the United States Internal Revenue Service (“IRS”) described in Note 11.

The Cooperation Agreement Amendment provides for the Rehabilitator to have certain rights with respect to (a) the tax positions taken by the Company in its consolidated tax return; (b) the acceptance by Ambac Assurance of the repayment of intercompany loans or the modification of the terms thereof; (c) changes by Ambac Assurance in the assumptions or vendors utilized in determining loss reserves determined in accordance with Statutory Accounting Principles; and (d) changes to Ambac Assurance’s investment policy and transfer of the investment management function for Ambac Assurance’s investment portfolio.

The Amended Plan Settlement, Mediation Agreement, Amended TSA, Cost Allocation Agreement and Cooperation Agreement Amendment collectively memorialize the settlement of certain claims among the Company and Ambac Assurance, OCI and the Segregated Account, and contain broad releases of the Company, Ambac

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Assurance, the Segregated Account, OCI, the board of directors and board committees of the Company and Ambac Assurance, all current and former individual directors, officers, or employees of the Company and Ambac Assurance, the Creditors’ Committee and the individual members thereof, and certain other released parties.

Consummation of the Reorganization Plan is subject to the satisfaction or waiver of the following conditions: (i) the Bankruptcy Court shall have entered an order confirming the Reorganization Plan and such order shall have become final in accordance with the Reorganization Plan; (ii) the Bankruptcy Court shall have approved any supplement filed with respect to the Reorganization Plan; (iii) new organizational documents of the Company shall have been effected; (iv) the Company shall have executed and delivered all documents necessary to effectuate the issuance of the common stock and warrants (if applicable) pursuant to the Reorganization Plan; (v) all authorizations, consents and regulatory approvals required, if any, in connection with the consummation of the Reorganization Plan shall have been obtained; (vi) the Stipulation (as defined in Note 11) shall have become effective; (vii) the terms of the IRS Settlement (as defined in Note 11) shall have been approved by OCI, the United States, the Rehabilitation Court, and the Creditors’ Committee, and all conditions to the effectiveness of the IRS Settlement shall have been satisfied; (viii) the IRS Settlement and all transaction documents relating thereto shall have been executed by the parties thereto; (ix) the Bankruptcy Court shall have entered an order pursuant to Bankruptcy Rule 9019 approving the IRS Settlement; (x) the aggregate face amount of allowed and disputed general unsecured claims shall be less than $50,000; (xi) the Rehabilitation Court shall have approved the transactions contemplated by the Mediation Agreement, the Amended TSA, the Cost Allocation Agreement, and the Cooperation Agreement Amendment; (xii) $30,000 shall have been paid or paid into escrow by Ambac Assurance as provided in the Mediation Agreement; (xiii) the Amended TSA, the Cooperation Agreement Amendment and the Cost Allocation Agreement shall have been executed; and (xiv) all other actions, documents, certificates and agreements necessary to implement the Reorganization Plan shall have been effected or executed and delivered to the required parties and, to the extent required, filed with applicable governmental units in accordance with applicable laws. Of the conditions enumerated above, the following have been satisfied: (i); (x); (xi); (xii) and (xiii). There can be no assurance about whether or when the remaining conditions will be met.

Ambac’s principal business strategy is to reorganize its capital structure and financial obligations through the bankruptcy process and to increase the residual value of its financial guarantee business by mitigating losses on poorly performing transactions (via the pursuit of recoveries in respect of paid claims, commutations of policies, purchases of Ambac-insured obligations, and repurchases of surplus notes issued by Ambac Assurance or the Segregated Account) and maximizing the return on its investment portfolio. The execution of such strategy with respect to liabilities allocated to the Segregated Account is subject to the authority of the Rehabilitator to control the management of the Segregated Account. In exercising such authority, the Rehabilitator will act for the benefit of policyholders, and will not take into account the interests of Ambac. Similarly, by operation of the contracts executed in connection with the establishment, and subsequent rehabilitation, of the Segregated Account, the Rehabilitator retains rights to oversee and approve certain actions taken in respect of Ambac Assurance. This oversight by the Rehabilitator could impair Ambac’s ability to execute the foregoing strategy. As a result of uncertainties associated with the aforementioned factors, management has concluded that there is substantial doubt about the ability of the Company to continue as a going concern. The Company’s financial statements as of March 31, 2012 and 2011 and for the periods ended March 31, 2012 and 2011 are prepared assuming the Company continues as a going concern and do not include any adjustment that might result from its inability to continue as a going concern.

Ambac’s liquidity and solvency are largely dependent on its current cash and investments of $33,994 at March 31, 2012 (excluding $2,500 of restricted cash), consummation of the Reorganization Plan, and on the residual value of Ambac Assurance. The principal uses of liquidity are the payment of operating expenses, professional advisory fees incurred in connection with the bankruptcy and expenses related to pending litigation. Management believes that Ambac will have sufficient liquidity to satisfy its needs until it emerges from the bankruptcy proceeding; however, no assurance can be given regarding the timing or certainty of such emergence. If its cash and investments run out prior to emergence from bankruptcy, a liquidation of Ambac pursuant to Chapter 7 of the Bankruptcy Code will occur.

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2. Debtor in Possession Financial Information

Liabilities Subject to Compromise

As required by ASC Topic 852, Reorganizations, the amount of the Liabilities Subject to Compromise represents our estimate of known or potential pre-petition and post-petition claims to be addressed in connection with the Bankruptcy Filing. Such claims are subject to future adjustments. The Liabilities subject to compromise in the Consolidated Balance Sheet consists of the following:

Interest was no longer accrued on Ambac’s debt obligations included in Liabilities Subject to Compromise on the Consolidated Balance Sheets after Ambac filed for bankruptcy protection on November 8, 2010. If Ambac had continued to accrue interest on its debt obligations, contractual interest expense would have been $24,162 and $28,576 for the three months ended March 31, 2012 and 2011, respectively.

Reorganization Items, net

Professional advisory fees and other costs directly associated with our reorganization are reported separately as reorganization items pursuant to ASC Topic 852. Reorganization items also include adjustments to reflect the carrying value of certain pre-petition liabilities at their estimated allowable claim amounts. The reorganization items in the Consolidated Statements of Total Comprehensive Income for the three months ended March 31, 2012 and 2011, consisted of the following items:

3. Net Premiums Earned

Gross premiums are received either upfront (typical of public finance obligations) or in installments (typical of structured finance obligations). For premiums received upfront, an unearned premium revenue (“UPR”) liability is established, which is initially recorded as the cash amount received. For installment premium transactions, a premium receivable asset and offsetting UPR liability is initially established in an amount equal to: (i) the present value of future contractual premiums due (the “contractual” method) or, (ii) if the underlying insured obligation is a homogenous pool of assets which are contractually prepayable, the present value of premiums to be collected over the expected life of the transaction (the “expected” method). An appropriate risk-free rate corresponding to the weighted average life of each policy and exposure currency is used to discount the future premiums contractually

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due or expected to be collected. For example, U.S. dollar exposures are discounted using U.S. Treasury rates while exposures denominated in a foreign currency are discounted using the appropriate risk-free rate for the respective currency. The weighted average risk-free rate at March 31, 2012 and December 31, 2011 was 2.7% and 2.6%, respectively, and the weighted average period of future premiums used to estimate the premium receivable at March 31, 2012, and December 31, 2011 was 10.2 years and 10.0 years, respectively.

Insured obligations consisting of homogeneous pools for which Ambac uses expected future premiums to estimate the premium receivable and UPR include residential mortgage-backed securities and consumer auto loans. As prepayment assumptions change for homogenous pool transactions, or if there is an actual prepayment for a “contractual” method installment transaction, the related premium receivable and UPR are adjusted in equal and offsetting amounts with no immediate effect on earnings using new premium cash flows and the then current risk free rate.

Generally, the priority for the payment of financial guarantee premiums to Ambac, as required by the bond indentures of the insured obligations, is very senior in the waterfall. Additionally, in connection with the allocation of certain liabilities to the Segregated Account, trustees are required under the Segregated Account Rehabilitation Plan and related court orders to continue to pay installment premiums, notwithstanding the claims moratorium. In evaluating the credit quality of the premiums receivable, management evaluates i.) the internal ratings of the transactions underlying the premiums receivable, and, as applicable, ii.) expected future premium collections for transactions for which loss reserves have been recognized. As of March 31, 2012, and December 31, 2011 approximately 44% and 43% of the premiums receivable related to transactions with non-investment grade internal ratings, comprised mainly of non-investment grade MBS and student loan transactions, which comprised 12% and 11%, respectively, of the total premiums receivable at March 31, 2012, and December 31, 2011. For the three months ended March 31, 2012, $4,417 of premium receivables relating to a non-investment obligation were deemed uncollectible and written off. At March 31, 2012, past due premiums on policies insuring non-investment grade obligations that were not written off amounted to less than $200.

For both upfront and installment premium policies, premium revenues are earned over the life of the financial guarantee contract in proportion to the insured principal amount outstanding at each reporting date (referred to as the level-yield method). For installment paying policies, the premium receivable discount, equating to the difference between the undiscounted future installment premiums and the present value of future installment premiums, is accreted as premiums earned in proportion to the premium receivable balance at each reporting date. Because the premium receivable discount and UPR are being accreted into income using different rates, the total premiums earned as a percentage of insured principal is higher in the earlier years and lower in the later years for an installment premium transaction as compared to an upfront premium transaction. Below is the premium receivable roll-forward for the periods ended March 31, 2012, and December 31, 2011:

Similar to gross premiums, premiums ceded to reinsurers are paid either upfront or in installments. For premiums paid upfront, a deferred ceded premium asset is established which is initially recorded as the cash amount paid. For installment premiums, a ceded installment premiums payable liability and offsetting deferred ceded premium asset are initially established in an amount equal to: i) the present value of future contractual premiums due or, ii) if the underlying insured obligation is a homogenous pool of assets which are contractually prepayable, the

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present value of expected premiums to be paid over the life of the transaction. An appropriate risk-free rate corresponding to the weighted average life of each policy and exposure currency is used to discount the future premiums contractually due or expected to be collected. Premiums ceded to reinsurers reduce the amount of premiums earned by Ambac from its financial guarantee insurance policies. For both up-front and installment premiums, ceded premiums written are primarily recognized in earnings in proportion to and at the same time as the related gross premium revenue is recognized. For premiums paid to reinsurers on an installment basis, Ambac records the present value of future ceding commissions as an offset to ceded premiums payable, using the same assumptions noted above for installment premiums. The ceding commission revenue associated with the ceding premiums payable is deferred (as an offset to deferred acquisition cost) and recognized in income in proportion to ceded premiums.

The table below summarizes the future gross undiscounted premiums expected to be collected, and future expected premiums earned, net of reinsurance at March 31, 2012:

When a bond issue insured by Ambac Assurance has been retired, including those retirements due to refundings or calls, any remaining UPR is recognized at that time to the extent the financial guarantee insurance policy is legally extinguished. For installment premium paying transactions, we offset the recognition of any remaining UPR by the reduction of the related premium receivable to zero (as it will not be collected as a result of the retirement), which may cause negative accelerated premium revenue. Accelerated premium revenue for retired

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obligations for three months ended March 31, 2012 and 2011 was $15,790 and ($70), respectively. The table below shows premiums written on a gross and net basis for the three month periods ended March 31, 2012 and 2011:

4. Net Income Per Share

Basic net income per share is computed by dividing net income available to common stockholders by the weighted-average number of common shares outstanding. Common shares outstanding includes common stock issued less treasury shares plus restricted stock units for which no future service is required as a condition to the delivery of the underlying common stock. Diluted net income per share is computed by dividing net income attributable to common stockholders by the weighted-average number of common shares outstanding plus all dilutive potential common shares outstanding during the period. All dilutive potential common shares outstanding consider common stock deliverable pursuant to stock options and nonvested restricted stock units. These dilutive shares totaled 114,269 from the assumed settlement of dilutive nonvested restricted stock units at March 31, 2012. The number of additional shares is calculated by assuming that nonvested restricted stock units were settled and that the proceeds from such exercises were used to acquire shares of common stock at the average market price during the period. There were no dilutive effects for the period ended March 31, 2011. The following table presents securities outstanding that could potentially dilute basic EPS in the future that were not included in the computation of diluted EPS because they were antidilutive for the periods ended March 31, 2012 and 2011:

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5. Special Purpose Entities, Including Variable Interest Entities

Ambac has engaged in transactions with special purpose entities, including VIEs, in various capacities. Ambac most commonly has provided financial guarantees, including credit derivative contracts, for various debt obligations issued by special purpose entities, including VIEs. Ambac has also sponsored two special purpose entities that issued medium-term notes to fund the purchase of certain financial assets. Ambac is also an investor in collateralized debt obligations, mortgage-backed and other asset-backed securities issued by VIEs and its ownership interest is generally insignificant to the VIE and/or Ambac does not have rights that direct the activities that are most significant to such VIE. In 2011, Ambac entered into a secured borrowing transaction under which two VIEs were created for the purpose of resecuritizing certain invested assets and collateralizing the borrowing. These VIEs are consolidated because Ambac was involved in their design and holds a significant amount of the beneficial interests issued by the VIEs. VIE debt outstanding to third parties under this secured borrowing transaction was $28,320 and $35,600 as of March 31, 2012 and December 31, 2011, respectively. The debt represents the senior-most tranche of the securitization structure and is to be repaid from the non-insurance proceeds of certain RMBS securities which are guaranteed by Ambac Assurance. Such securities had a fair value of $179,339 and $172,880 as of March 31, 2012 and December 31, 2011, respectively. Refer to Note 8, Investments for further discussion of the restrictions on these securities.

Financial Guarantees:

Ambac has provided financial guarantees in respect of assets held or debt obligations of special purpose entities, including VIEs. Ambac’s primary variable interest exists through this financial guarantee insurance or credit derivative contract. The transaction structure provides certain financial protection to Ambac. This financial protection can take several forms; however, the most common are over-collateralization, first loss and excess spread. In the case of over-collateralization (i.e., the principal amount of the securitized assets exceeds the principal amount of the debt obligations guaranteed by Ambac Assurance), the structure allows the transaction to experience defaults among the securitized assets before a default is experienced on the debt obligations that have been guaranteed by Ambac Assurance. In the case of first loss, the financial guarantee insurance policy only covers a senior layer of losses on assets held or debt issued by special purpose entities, including VIEs. The first loss with respect to the assets is either retained by the asset seller or sold off in the form of equity or mezzanine debt to other investors. In the case of excess spread, the securitized assets contributed to special purpose entities, including VIEs, generate interest cash flows that are in excess of the interest payments on the related debt; such excess cash flow is applied to redeem debt, thus creating over-collateralization. Generally, upon deterioration in the performance of a transaction or upon an event of default as specified in the transaction legal documents, Ambac will obtain certain loss remediation rights. These rights may enable Ambac to direct the activities of the entity that most significantly impact the entity’s economic performance.

We determined that Ambac generally has the obligation to absorb the VIE’s expected losses given that we have issued financial guarantees supporting the liabilities (and in certain cases assets) of a VIE. We also determined for certain transactions that experienced the aforementioned performance deterioration, that we had the power, through voting rights or similar rights, to direct the activities of certain VIEs that most significantly impact the VIE’s economic performance because: a) certain triggers had been breached in these transactions resulting in Ambac having the ability to exercise certain loss remediation activities, or b) due to the passive nature of the VIEs’ activities, Ambac’s contingent loss remediation rights upon a breach of certain triggers in the future is considered to be the power to direct the activities that most significantly impact the VIEs’ economic performance. With respect to existing VIEs involving Ambac financial guarantees, Ambac is generally required to consolidate a VIE in the period that applicable triggers result in Ambac having control over the VIE’s most significant economic activities. A VIE is deconsolidated in the period that Ambac no longer has such control, which generally occurs in connection with allocation to the Segregated Account, execution of remediation activities on the transaction or amortization of insured exposure, any of which may reduce the degree of Ambac’s control over a VIE.

Ambac Sponsored VIEs:

A subsidiary of Ambac has transferred financial assets to two special purpose entities. The business purpose of these entities is to provide certain financial guarantee clients with funding for their debt obligations. These special

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purpose entities are legal entities that are demonstrably distinct from Ambac. Ambac, its affiliates or its agents cannot unilaterally dissolve these entities. The permitted activities of these entities are limited to those outlined below. Ambac does not consolidate these entities because Ambac’s policies issued to these entities have been allocated to the Segregated Account, thereby limiting Ambac’s control over the entities’ most significant economic activities. Ambac has elected to account for its equity interest in these entities at fair value under the fair value option in accordance with ASC Topic 825, Financial Instruments. We believe that the fair value of the investments in these entities provides for greater transparency for recording profit or loss as compared to the equity method under ASC Topic 323, Investments—Equity Method in Joint Ventures. Refer to Note 7 for further information on the valuation technique and inputs used to measure the fair value of Ambac’s equity interest in these entities. At March 31, 2012 and December 31, 2011 the fair value of these entities is $16,023 and $16,779, respectively, and is reported within Other assets on the Consolidated Balance Sheets. The change in fair value of these entities is ($756) and $1,096 for the three months ended March 31, 2012 and 2011, respectively.

Since their inception, there have been 15 individual transactions with these entities, of which 5 transactions were outstanding as of March 31, 2012. Total principal amount of debt outstanding was $576,387 and $578,562 at March 31, 2012 and December 31, 2011, respectively. In each case, Ambac sold assets to these entities. The assets are composed of asset-backed securities and utility obligations with a weighted average rating of A- at March 31, 2012 and weighted average life of 8.1 years. The purchase by these entities was financed through the issuance of medium-term notes (“MTNs”), which are cross-collateralized by the purchased assets. The MTNs have the same expected weighted average life as the purchased assets. Derivative contracts (interest rate swaps) are used within the entities for economic hedging purposes only. Hedges are established at the time MTNs are issued to purchase financial assets. The activities of these entities are contractually limited to purchasing assets from Ambac, issuing MTNs to fund such purchase, executing derivative hedges and obtaining financial guarantee policies with respect to indebtedness incurred. As of March 31, 2012 Ambac Assurance had financial guarantee insurance policies issued for all assets, MTNs and derivative contracts owned and outstanding by the entities.

Insurance premiums paid to Ambac Assurance by these entities are earned in a manner consistent with other insurance policies, over the risk period. Additionally, any losses incurred on such insurance policies are included in Ambac’s Consolidated Statements of Total Comprehensive Income. Under the terms of an Administrative Agency Agreement, Ambac provides certain administrative duties, primarily collecting amounts due on the obligations and making interest payments on the MTNs.

There were no assets sold to these entities during the three months ended March 31, 2012 and 2011. Ambac Assurance earned premiums for issuing the financial guarantee policies on the assets, MTNs and derivative contracts of $145 and $235 for the three months ended March 31, 2012 and 2011, respectively. Ambac paid no claims to these entities under its financial guarantee policies for the three months ended March 31, 2012 and 2011. Ambac also earned fees for providing other services amounting to $11 and $11 for the three months ended March 31, 2012 and 2011, respectively.

Derivative contracts are provided by Ambac Financial Services to these entities. Consistent with other derivatives, Ambac Financial Services (“AFS”) accounts for these contracts on a trade date basis at fair value. AFS paid $138 and $131 for the three months ended March 31, 2012 and 2011, respectively, under these derivative contracts.

Consolidation of VIEs:

Upon initial consolidation of a VIE, we recognize a gain or loss in earnings for the difference between: a) the fair value of the consideration paid, the fair value of any non-controlling interests and the reported amount of any previously held interests and b) the net amount, as measured on a fair value basis, of the assets and liabilities consolidated. Upon deconsolidation of a VIE, we recognize a gain or loss for the difference between: a) the fair value of any consideration received, the fair value of any retained non-controlling investment in the VIE and the carrying amount of any non-controlling interest in the VIE and b) the carrying amount of the VIE’s assets and liabilities. Gains or losses from consolidation and deconsolidation that are reported in earnings are reported within Income (loss) on variable interest entities.

The variable interest in VIE generally involves one or more of the following: a financial guarantee policy issued to the VIE, a written credit derivative contract that references liabilities of the VIE or an investment in

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securities issued by the VIE. The impact of consolidating such VIEs on Ambac’s balance sheet is follows. For a financial guarantee policy issued to a consolidated VIE, Ambac does not reflect the financial guarantee insurance policy in accordance with the related insurance accounting rules under ASC Topic 944, Financial Services—Insurance. The financial guarantee policy would be eliminated upon consolidation. Consequently, Ambac eliminates insurance assets (premium receivables, reinsurance recoverable, deferred ceded premium, subrogation recoverable and deferred acquisition costs) and insurance liabilities (unearned premiums, loss and loss expense reserves and ceded premiums payable) from the Consolidated Balance Sheets. For investment securities owned by Ambac that are debt instruments issued by the VIE, the investment securities balance is eliminated upon consolidation.

Income (loss) on variable interest entities included losses of $0 and $8,422 for the three month periods ended March 31, 2012 and 2011, respectively, related to VIEs that were no longer consolidated as of the end the respective periods. Such losses for the three months ended March 31, 2011 primarily related to the impact of deconsolidating a VIE during that period.

As of March 31, 2012, consolidated VIE assets and liabilities relating to 18 consolidated entities were $16,857,878 and $16,672,670, respectively. As of December 31, 2011, consolidated VIE assets and liabilities relating to 19 consolidated entities were $16,543,207 and $16,379,386, respectively. Ambac is not primarily liable for, and does not guarantee all of the debt obligations issued by the VIEs. Ambac would only be required to make payments on the guaranteed debt obligations in the event that the issuer of such debt obligations defaults on any principal or interest due. Additionally, Ambac’s creditors do not have rights with regard to the assets of the VIEs. Ambac evaluates the net income statement effects and earnings per share effects to determine attributions between Ambac and non-controlling interests as a result of consolidating a VIE. Ambac has determined that the net changes in fair value of most consolidated VIE assets and liabilities are attributable to Ambac due to Ambac’s interest through financial guarantee premium and loss payments with the VIE.

The financial reports of certain VIEs are prepared by outside trustees and are not available within the time constraints Ambac requires to ensure the financial accuracy of the operating results. As such, the financial results of certain VIEs are consolidated on a time lag that is no longer than 90 days.

The table below provides the fair value of fixed income securities, by asset-type, held by consolidated VIEs as of March 31, 2012 and December 31, 2011:

The following table provides supplemental information about the loans held as assets and long-term debt associated with the VIEs for which the fair value option has been elected as of March 31, 2012 and December 31, 2011:

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Variable Interests in Non-Consolidated VIEs

The following table displays the carrying amount of the assets, liabilities and maximum exposure to loss of Ambac’s variable interests in non-consolidated VIEs resulting from financial guarantee and credit derivative contracts by major underlying asset classes, as of March 31, 2012 and December 31, 2011: