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): February 25, 2003 ----------------- NORTHWEST PIPELINE CORPORATION (Exact name of registrant as specified in its charter) <Table> DELAWARE 1-7414 87-0269236 (State or other jurisdiction (Commission File Number) (I.R.S. Employer of incorporation) Identification No.) 295 CHIPETA WAY 84108 SALT LAKE CITY, UTAH (Zip Code) (Address of principal executive offices) </Table> Registrant's telephone number, including area code: 801-583-8800 NOT APPLICABLE (Former name or former address, if changed since last report) ITEM 9. REGULATION FD DISCLOSURE Northwest Pipeline Corporation wishes to disclose for Regulation FD purposes its Management's Narrative Analysis of the Results of Operations, Audited Financial Statements and Supplementary Data, and Notes to Financial Statements for the year ended December 31, 2002, as set forth in Exhibit 99.1 attached hereto. Northwest Pipeline Corporation's independent auditors, Ernst & Young LLP, consent to filing of the information contained herein as set forth in Exhibit 99.2. 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. NORTHWEST PIPELINE CORPORATION By: /s/ Brian K. Shore --------------------- Name: Brian K. Shore Title: Corporate Secretary Dated: February 26, 2003 2 INDEX TO EXHIBITS <Table> <Caption> EXHIBIT NUMBER DESCRIPTION - ------ ----------- 99.1 Northwest Pipeline Corporation's Management's Narrative Analysis of the Results of Operations, Financial Statements and Supplementary Data, and Notes to Financial Statements for the year ended December 31, 2002. 99.2 Consent of Independent Auditors. </Table> 3