SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 12b-25

Notification of Late Filing

Commission File Number: 001-32647

(Check one)	¨  Form 10-K     ¨  Form 20-F     ¨  Form 11-K     x  Form 10-Q ¨  Form 10-D     ¨  Form N-SAR     ¨  Form N-CSR
	For period ended June 30, 2012
	¨  Transition Report on Form 10-K
	¨  Transition Report on Form 20-F
	¨  Transition Report on Form 11-K
	¨  Transition Report on Form 10-Q
	¨  Transition Report on Form N-SAR
	For the transition period ended

Read Attached Instruction Sheet Before Preparing Form. Please Print or Type.

Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the item(s) to which the notification relates:

PART I REGISTRANT INFORMATION

ATP OIL & GAS CORPORATION

Full name of registrant:

Former name if applicable:

4600 Post Oak Place, Suite 100

Address of principal executive office (Street and Number):

Houston, Texas 77027

City, State and Zip Code:

PART II RULES 12B-25(b) AND (c)

If the subject report could not be filed without unreasonable effort or expense and the registrant seeks relief pursuant to Rule 12b-25(b), the following should be completed. (Check box if appropriate.)

¨	(a)	The reasons described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense;
	(b)	The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and
	(c)	The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

PART III NARRATIVE

State below in reasonable detail the reasons why Forms 10-K, 20-F, 11-K, 10-Q, 10-D, N-SAR or N-CSR, or the transition report portion thereof, could not be filed within the prescribed time period. (Attach extra sheets if needed.)

ATP Oil & Gas Corporation (the “Company”) was unable to file its Quarterly Report on Form 10-Q for the quarter ended June 30, 2012 due to the difficulty in completing and obtaining the required financial and other information without unreasonable effort and expense.

PART IV OTHER INFORMATION

(1) Name and telephone number of person to contact in regard to this notification.

Albert L. Reese Jr.	(713)	622-3311
(Name)	(Area Code)	(Telephone Number)

(2) Have all other periodic reports required under Section 13 or 15(d) or the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months (or for such shorter period) that the registrant was required to file such report(s) been filed? If the answer is no, identify report(s).    x  Yes    ¨  No

(3) Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?    ¨  Yes    x  No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

As of the date of this filing, the Company is unable to determine whether or not there will be any significant changes in its results of operations from the quarter ended June 30, 2011 as it is still in the process of compiling the information necessary for the preparation of its financial statements as described above.

ATP Oil & Gas Corporation

(Name of Registrant as Specified in Charter)

has caused this notification to be signed on its behalf by the undersigned thereunto duly authorized.

Date:	August 10, 2012	By:	/s/ Albert L. Reese Jr.
			Albert L. Reese Jr.
			Chief Financial Officer