Exhibit 99

NEWS

ANADARKO ANNOUNCES SECOND-QUARTER RESULTS

HOUSTON, July 25, 2011 – Anadarko Petroleum Corporation (NYSE: APC) today announced second-quarter 2011 net income attributable to common stockholders of $544 million, or $1.08 per share (diluted). These results include certain items typically excluded by the investment community in published estimates. In total, these items decreased net income by approximately $28 million, or $0.06 per share (diluted) on an after-tax basis.⁽¹⁾ Cash flow from operating activities in the second quarter of 2011 was $1.837 billion, and discretionary cash flow totaled $1.838 billion.⁽²⁾

SECOND-QUARTER 2011 HIGHLIGHTS

“We achieved record liquids sales volumes during the quarter, enhancing margins and generating excellent cash flows,” said Anadarko Chairman and CEO Jim Hackett. “Nearly all of the year-over-year volume growth was attributable to a 34,000 barrel-per-day increase in liquids volumes. These results contributed to strong discretionary cash flows of more than $1.8 billion – approximately $117 million above our capital expenditures, which included a one-time cash investment of $518 million associated with the acquisition of the Wattenberg plant.”

During the second quarter of 2011, sales volumes totaled 62 million barrels of oil equivalent (BOE), or 685,000 BOE per day, averaging approximately 2.3 billion cubic feet of natural gas per day, 225,000 barrels of oil per day (BOPD), and 72,000 barrels of natural gas liquids per day.

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OPERATIONS SUMMARY

The company achieved sales-volumes records during the second quarter of 2011 in Wattenberg, Greater Natural Buttes, Wamsutter (operated), Bone Spring and the Marcellus Shale. In the Eagleford Shale, Anadarko closed its $1.6 billion joint-venture agreement with a subsidiary of Korea National Oil Corporation and exited the quarter with record gross sales volumes of approximately 45,000 BOE per day in the play, an increase of approximately 25 percent from the end of the prior quarter. In Ghana, current gross production from Jubilee is approximately 80,000 BOPD, and production continues to ramp up with further well completions and gas injection.

In the deepwater Gulf of Mexico, Anadarko continued to advance two major projects during the second quarter. The company finalized the Lucius unitization agreement and recently announced plans to develop the field with a truss spar designed for a capacity of 80,000 BOPD and 450 million cubic feet of natural gas per day. Sanctioning is expected to occur later this year, with first production expected in 2014. At the Caesar/Tonga project, Anadarko completed flow and reservoir tests on three wells. Each of the wells tested at flow rates of approximately 15,000 BOPD with high-quality (27º API gravity) oil.

EXPLORATION SUMMARY

Anadarko has mobilized the Discoverer Spirit drillship to begin the company’s 2011 exploration program in West Africa, following the drillship’s completion of the final test at Caesar/Tonga. This program includes the Montserrado exploration well in Liberia, as well as the Jupiter exploration well and Mercury appraisal well in Sierra Leone. In other deepwater exploration areas, Anadarko continued to delineate its large natural gas discoveries in Mozambique, and to advance appraisal activities in the Tweneboa/Enyenra area offshore Ghana. The company also recently began appraisal drilling in the Campos Basin offshore Brazil.

As previously announced by Diamond Offshore, Anadarko signed long-term contracts in the second quarter for two new-build drillships. The Ocean BlackHawk is expected to be delivered in late 2013, and the Ocean BlackHornet is expected to be delivered in early 2014. These new state-of-the-art rigs are designed to work in up to 12,000 feet of water, and each

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has been contracted for a term of five years. These new rigs will feature enhanced drilling capabilities and safety equipment designed to meet the highest specifications in the industry.

“We expect the next six to nine months to be the most active period of deepwater exploration and appraisal drilling in our company’s history,” said Hackett. “Our exploration program is designed to deliver upon our goal of discovering more than 500 million BOE of net risked resources this year. We are continuing to advance our deep inventory of high-impact prospects, and the new rig agreements reinforce our long-term commitment to the safety and success of our global exploration program.”

FINANCIAL SUMMARY

Anadarko reported total product revenues of approximately $3.5 billion during the second quarter of 2011, a 46-percent increase relative to the second quarter of 2010. The company ended the second quarter of 2011 with approximately $3.4 billion of cash on hand in addition to its five-year, $5 billion undrawn credit facility. As provided in the supplemental information to this release, Anadarko protected an additional 450,000 MMBtu per day of 2013 natural gas production, with three-way collars that have a middle floor of $5.00 per MMBtu and a ceiling of $6.57 per MMBtu.

OPERATIONS REPORT

For more details on Anadarko’s operations, please refer to the comprehensive report on second-quarter 2011 activity. The report is available at www.anadarko.com on the Investor Relations page.

CONFERENCE CALL TOMORROW AT 9 A.M. CDT, 10 A.M. EDT

Anadarko will host a conference call on Tuesday, July 26, at 9 a.m. Central Daylight Time (10 a.m. Eastern Daylight Time) to discuss second-quarter results, current operations and the company’s outlook for the remainder of 2011. The dial-in number is 888.713.4205 in the United States or 617.213.4862 internationally. The confirmation number is 67183355. For complete instructions on how to participate in the conference call, or to listen to the live audio webcast and slide presentation, please visit www.anadarko.com. A replay of the call will also

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be available on the Web site for approximately 30 days following the conference call.

FINANCIAL DATA

Eight pages of summary financial data follow, including current hedge positions, financial guidance and supplemental production guidance.

⁽¹⁾ See the accompanying table for details of certain items affecting comparability.

⁽²⁾ See the accompanying table for a reconciliation of GAAP to non-GAAP financial measures and a statement indicating why management believes the non-GAAP financial measures provide useful information for investors.

Anadarko Petroleum Corporation’s mission is to deliver a competitive and sustainable rate of return to shareholders by exploring for, acquiring and developing oil and natural gas resources vital to the world’s health and welfare. As of year-end 2010, the company had approximately 2.42 billion barrels-equivalent of proved reserves, making it one of the world’s largest independent exploration and production companies. For more information about Anadarko, please visit www.anadarko.com.

This news release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Anadarko believes that its expectations are based on reasonable assumptions. No assurance, however, can be given that such expectations will prove to have been correct. A number of factors could cause actual results to differ materially from the projections, anticipated results or other expectations expressed in this news release, including Anadarko’s ability to commercially operate the drilling prospects identified in this news release. See “Risk Factors” in the company’s 2010 Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and other public filings and press releases. Anadarko undertakes no obligation to publicly update or revise any forward-looking statements.

Cautionary Note to U.S. Investors: Effective Jan. 1, 2010, the United States Securities and Exchange Commission (“SEC”) permits oil and gas companies, in their filings with the SEC, to disclose only proved, probable and possible reserves that meet the SEC’s definitions for such terms. Anadarko uses certain terms in this news release, such as “net risked resources,” and similar terms that the SEC’s guidelines strictly prohibit Anadarko from including in filings with the SEC. U.S. investors are urged to consider closely the disclosure in Anadarko’s Form 10-K for the year ended Dec. 31, 2010, File No. 001-08968, available from Anadarko at www.anadarko.com or by writing Anadarko at: Anadarko Petroleum Corporation, 1201 Lake Robbins Drive, The Woodlands, Texas 77380, Attn: Investor Relations. This form may also be obtained by contacting the SEC at 1-800-SEC-0330.

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ANADARKO CONTACTS

MEDIA:

John Christiansen, john.christiansen@anadarko.com, 832.636.8736

Brian Cain, brian.cain@anadarko.com, 832.636.3404

INVESTORS:

John Colglazier, john.colglazier@anadarko.com, 832.636.2306

Clay Gaspar, clay.gaspar@anadarko.com, 832.636.2541

Wayne Rodrigs, wayne.rodrigs@anadarko.com, 832.636.2305

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Reconciliation of GAAP to Non-GAAP Measures

Below are reconciliations of cash provided by operating activities (GAAP) to discretionary cash flow from operations and free cash flow (non-GAAP), and net income (loss) attributable to common stockholders (GAAP) to adjusted net income (loss) (non-GAAP) as required under Regulation G of the Securities Exchange Act of 1934. Management uses discretionary cash flow from operations and free cash flow to demonstrate the Company’s ability to internally fund capital expenditures and to service or incur additional debt. It is useful in comparisons of oil and gas exploration and production companies because it excludes fluctuations in assets and liabilities. Management uses adjusted net income (loss) to evaluate the Company’s operational trends and performance.

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Anadarko Petroleum Corporation

Reconciliation of GAAP to Non-GAAP Measures

Presented below is a reconciliation of total debt (GAAP) to net debt (non-GAAP). Management uses net debt as a measure of the Company’s outstanding debt obligations that would not be readily satisfied by its cash and cash equivalents on hand.

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Anadarko Petroleum Corporation

(Unaudited)

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Anadarko Petroleum Corporation

(Unaudited)

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Anadarko Petroleum Corporation

(Unaudited)

Sales Volumes and Prices