Filed by Ensco plc
Pursuant to Rule 425 of the Securities Act of 1933, as amended, and
deemed filed pursuant to Rule 14a-12 of the Securities Exchange Act of 1934, as amended
Subject Company: Pride International, Inc.
Commission File No: 001-13289

7 February 2011

RE: Ensco To Acquire Pride International

Dear [Valued Customer]:

Today, we announced that the Boards of Directors of Ensco and Pride have approved a merger agreement to combine our two companies — creating the world’s second largest offshore driller. A copy of the press release is attached for your review.

First and foremost, our companies share a dedication to safety, operational excellence, customer satisfaction, employee development and disciplined risk management, so you can continue to expect the highest levels of service from the combined company.

Going forward, given the complementary makeup of our respective businesses, we will be able to offer a wider range of drilling services — in more markets — with some of the newest and most capable drilling equipment in the industry. Many of our rigs have been delivered over the past five years and several new rigs are currently under construction. These investments will allow us to continue to offer you state-of-the-art drilling technologies well into the future.

The combined company will have 21 ultra-deepwater and deepwater rigs forming the second largest/youngest fleet of floaters able to drill in water depths of 4,500’ or greater. In addition, we will have more active premium jackups than any other driller and the third largest mid-water fleet.

Geographically, the combined company will have operations on six continents covering nearly every major deep- and shallow-water basin around the world. Regions will include the fastest-growing deepwater markets, Brazil and West Africa, as well as other major markets in Southeast Asia, the North Sea, Mediterranean, U.S. Gulf of Mexico, Mexico, Middle East and Australia.

Over the coming weeks, we expect to obtain the required regulatory and shareholder approvals in order to complete the acquisition in the second quarter of 2011. After the closing, we will begin to merge our two companies and we anticipate a smooth transition that will be seamless to our customers.

As always, we are grateful for your business and we appreciate the opportunity to provide you with the high-quality service you have come to expect.

Sincerely,

Forward-Looking Statements

Statements included in this document regarding the consummation of the proposed transaction, benefits, expected synergies and other expense savings and operational and administrative efficiencies, opportunities, timing, expense and effects of the transaction, contemplated financing of the transaction, financial performance, accretion to earnings, revenue growth, future dividend levels, credit ratings or other attributes of the combined companies and other statements that are not historical facts, are forward-looking statements. Forward-looking statements include words or phrases such as “anticipate,” “believe,” “contemplate,” “estimate,” “expect,” “intend,” “plan,” “project,” “could,” “may,” “might,” “should,” “will” and words and phrases of similar import. These statements involve risks and uncertainties including, but not limited to, actions by regulatory authorities, rating agencies or other third parties, actions by the respective companies’ security holders, costs and difficulties related to integration of acquired businesses, delays, costs and difficulties related to the transaction, market conditions, and the combined companies’ financial results and performance, consummation of financing, satisfaction of closing conditions, ability to repay debt and timing thereof, availability and terms of any financing and other factors detailed in risk factors and elsewhere in each company’s Annual Report on Form 10-K for the year ended December 31, 2009, and their respective other filings with the Securities and Exchange Commission (the “SEC”), which are available on the SEC’s website at www.sec.gov. Should one or more of these risks or uncertainties materialize (or the other consequences of such a development worsen), or should underlying assumptions prove incorrect, actual outcomes may vary materially from those forecasted or expected. All information in this document is as of today. Except as required by law, both companies disclaim any intention or obligation to update publicly or revise such statements, whether as a result of new information, future events or otherwise.

Important Additional Information Regarding The Transaction Will Be Filed With The SEC

In connection with the proposed transaction, Ensco will file a registration statement including a joint proxy statement/prospectus of Ensco and Pride with the SEC. INVESTORS AND SECURITY HOLDERS OF ENSCO AND PRIDE ARE ADVISED TO CAREFULLY READ THE REGISTRATION STATEMENT AND PROXY STATEMENT/PROSPECTUS (INCLUDING ALL AMENDMENTS AND SUPPLEMENTS TO IT) WHEN IT BECOMES AVAILABLE BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION ABOUT THE TRANSACTION, THE PARTIES TO THE TRANSACTION AND THE RISKS ASSOCIATED WITH THE TRANSACTION. A definitive joint proxy statement/prospectus will be sent to security holders of Ensco and Pride seeking their approval of the proposed transaction. Investors and security holders may obtain a free copy of the joint proxy statement/prospectus (when available) and other relevant documents filed by Ensco and Pride with the SEC from the SEC’s website at www.sec.gov. Security holders and other interested parties will also be able to obtain, without charge, a copy of the joint proxy statement/prospectus and other relevant documents (when available) by directing a request by mail or telephone to either Investor Relations, Ensco plc, 500 N. Akard, Suite 4300, Dallas, Texas 75201, telephone 214-397-3015, or Investor Relations, Pride International, Inc., 5847 San Felipe, Suite 3300, Houston, Texas 77057, telephone 713-789-1400. Copies of the documents filed by Ensco with the SEC will be available free of charge on Ensco’s website at www.enscoplc.com under the tab “Investors.” Copies of the documents filed by Pride with the SEC will be available free of charge on Pride’s website at www.prideinternational.com under the tab “Investor Relations.” Security holders may also read and copy any reports, statements and other information filed with the SEC at the SEC public reference room at 100 F Street N.E., Room 1580, Washington, D.C. 20549. Please call the SEC at (800) 732-0330 or visit the SEC’s website for further information on its public reference room.

Ensco and Pride and their respective directors, executive officers and certain other members of management may be deemed to be participants in the solicitation of proxies from their respective security holders with respect to the transaction. Information about these persons is set forth in Ensco’s proxy statement relating to its 2010 General Meeting of Shareholders and Pride’s proxy statement relating to its 2010 Annual Meeting of Stockholders, as filed with the SEC on 5 April 2010 and 1 April 2010, respectively, and subsequent statements of changes in beneficial ownership on file with the SEC. Security holders and investors may obtain additional information regarding the interests of such persons, which may be different than those of the respective companies’ security holders generally, by reading the joint proxy statement/prospectus and other relevant documents regarding the transaction, which will be filed with the SEC.