UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D. C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934

Date Of Report (Date of Earliest Event Reported) June 18, 2010

ATP OIL & GAS CORPORATION

(Exact name of registrant as specified in its charter)

4600 Post Oak Place, Suite 200

Houston, Texas 77027

(Address of principal executive offices)

(Zip Code)

(713) 622-3311

(Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On June 18, 2010, the Company entered into a Credit Agreement (the “Credit Agreement”) among the Company, Credit Suisse AG (“CS”), as administrative and collateral agent, and the lenders party thereto, providing for initial term loans of $150 million (the “Term Loans”). Closing and funding of the transaction is subject to normal and customary conditions precedent, which are expected to be satisfied no later than June 30, 2010.

The description set forth above in this Item 1.01 is qualified in its entirety by the Credit Agreement, which is filed as Exhibit 10.1 to this Current Report on Form 8-K and the contents thereof are incorporated herein by reference.

On June 18, 2010, the Company fully discharged all of its obligations to its lenders under that certain Credit Agreement, dated as of April 23, 2010, among the Company, JPMorgan Chase Bank, N.A., as administrative agent, Credit Suisse Securities (USA) LLC, as syndication agent, NATIXIS, as documentation agent, and the lenders party thereto (the “Former Credit Agreement”). The total amount repaid by the Company in satisfaction of its obligations was $0.2 million , representing commitment fees and related expenses. A copy of the Former Credit Agreement, which has been terminated, was attached as Exhibit 10.1 to the Company’s Current Report on Form 8-K filed with the Securities and Exchange Commission on April 29, 2010.

The information contained in Item 1.01 of this Form 8-K is hereby incorporated by reference into this Item 2.03. Capitalized terms used in this Item 2.03 and not defined shall have the meanings ascribed them in the Credit Agreement. Unless earlier payment is required under the Credit Agreement, the Term Loans must be paid on or before October 15, 2014.

Proceeds of the Term Loans are expected to be $144.3 million, net of original issue discount of $3.0 million and related transaction fees. Principal outstanding under the Term Loans bears interest at an annual rate of 11.0%. As security for the Company’s obligations under the Credit Agreement, the Company granted the lenders a security interest in and a first lien on, not less than 80% of the aggregate engineered present value of the Company’s proved oil and gas reserves located in, or in U.S. Federal waters adjacent to, the United States, capital stock of the Company’s material subsidiaries (limited in the case of the Company’s non-U.S. subsidiaries to not more than 65% of the capital stock of first-tier foreign subsidiaries) and, initially, certain infrastructure assets, which are subject to release.

The Company is required to pay the principal amounts on the dates set forth below, together in each case with accrued and unpaid interest on the principal amount to be paid:

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The Company is subject to certain negative covenants under the Credit Agreement. The provisions of the Credit Agreement limit the Company’s ability to, among other things:

The Credit Agreement also contains customary events of default, including, but not limited to, the following:

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(d) Exhibits.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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EXHIBIT INDEX

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