FILED BY KERR-MCGEE CORPORATION PURSUANT TO RULE 425 UNDER THE SECURITIES ACT OF 1933 AND DEEMED FILED PURSUANT TO RULE 14A-12 UNDER THE SECURITIES EXCHANGE ACT OF 1934 SUBJECT COMPANY: WESTPORT RESOURCES CORP. SUBJECT COMPANY SEC FILE NO. 001-14256 The merger agreement for Kerr-McGee Corporation's acquisition of Westport Resources Corporation, along with voting agreements and a registration rights agreement related to the merger agreement, were filed by Kerr-McGee Corporation under cover of Form 8-K today and are incorporated by reference into this filing. IMPORTANT LEGAL INFORMATION THE MERGER AGREEMENT AND RELATED AGREEMENTS ARE NOT AN OFFER TO SELL THE SECURITIES OF KERR-MCGEE CORPORATION AND IT IS NOT SOLICITING AN OFFER TO BUY THESE SECURITIES. INVESTOR AND SECURITY HOLDERS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE PROPOSED TRANSACTION WHEN IT BECOMES AVAILABLE BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION. The Joint Proxy Statement/Prospectus will be filed with the U.S. Securities and Exchange Commission (SEC) by Kerr-McGee Corporation and Westport Resources Corporation Investors and security holders may obtain a free copy of the Joint Proxy Statement/Prospectus when it becomes available and other documents filed or furnished by Kerr-McGee Corporation or Westport Resources Corporation with the SEC at the SEC's website, www.sec.gov. The Joint Proxy Statement/Prospectus and other documents filed or furnished by Kerr-McGee Corporation or Westport Resources Corporation may also be obtained for free by directing a request to Kerr-McGee Corporation, Attn: Corporate Secretary, P.O. Box 25861, Oklahoma City, Oklahoma 73125 or to Westport Resources Corporation, Attn: Investor Relations, 1670 Broadway, Suite 2800, Denver, Colorado 80202. Kerr-McGee, Westport Resources and their respective directors and officers may be deemed to be participants in the solicitation of proxies with respect to the transactions contemplated by the merger agreement. Information regarding Kerr-McGee's directors and officers is available in the Proxy Statement for its 2004 Annual Meeting of Stockholders, filed March 26, 2004 with the SEC, and its Annual Report on Form 10-K, filed March 12, 2004 with the SEC. Information regarding Westport Resources' directors and officers is available in the Proxy Statement for its 2003 Annual Meeting of Stockholders, filed April 21, 2003 with the SEC. Other information about the participants in the solicitation will be set forth in the Joint Proxy Statement/Prospectus and other relevant materials to be filed with the SEC. Safe Harbor Language on Forward Looking Statements: (Statements in the merger agreement and related agreements regarding the company's or management's intentions, beliefs or expectations, or that otherwise speak to future events, including resource estimates, production rate estimates, development schedule and cost estimates, are "forward-looking statements" within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements include those statements preceded by, followed by or that otherwise include the words "believes," "expects," "anticipates," "intends," "estimates," "projects," "target," "budget," "goal," "plans," "objective," "outlook," "should," or similar words. These "forward-looking" statements also include statements relating to (1) the impact the companies expect the proposed transaction to have on the combined entity's operations, financial condition, and financial results, (2) the companies' expectations about their ability to successfully integrate the combined businesses, (3) the amount of cost savings and overall operational efficiencies the companies expect to realize as a result of the proposed transaction, (4) when the companies expect to close the proposed transaction, (5) anticipated drilling and development opportunities and (6) the ability of the companies to meet their stated financial goals. In addition, any statements regarding possible commerciality, development plans, capacity expansions, drilling of new wells, ultimate recoverability of reserves, future production rates, future cash flows and changes in any of the foregoing are forward-looking statements. Matters discussed in these statements involve risks and uncertainties which may cause results to differ materially from those set forth in these statements. The following factors, among others, could cause actual results to differ from those set for in these forward-looking statements: the ability to obtain governmental approvals of the merger on the proposed terms and schedule; the failure of Kerr-McGee or Westport Resources stockholders to approve the merger; the risk that the businesses will not be integrated successfully; the risk that the cost savings and any synergies from the merger may not be fully realized or may take longer to realize than expected; disruption from the merger making it more difficult to maintain relationships with customers, employees or suppliers; the accuracy of the assumptions that underlie the statements, the success of the oil and gas exploration and production program, the price of oil and gas, drilling risks, uncertainties in interpreting engineering data, demand for consumer products for which Kerr-McGee's oil and gas business supplies raw materials, the financial resources of competitors, changes in laws and regulations, the ability to respond to challenges in international markets, including changes in currency exchange rates, political or economic conditions in areas where Kerr-McGee operates, trade and regulatory matters, general economic conditions, and other factors and risks identified in the Risk Factors sections of Kerr-McGee's Annual Report on Form 10-K and Westport Resources' Annual Report on Form 10-K as well as other of their SEC filings.