Exhibit 8.4 [LETTERHEAD OF MALLESONS STEPHEN JAQUES] November 3, 2003 BP Australia Capital Markets Limited Level 29 The Tower Melbourne Central 360 Elizabeth Street Melbourne VIC 3000 Australia Dear Sirs BP Australia Capital Markets Limited - Registration Statement on Form F-3 We have acted as Australian counsel to BP Australia Capital Markets Limited in connection with the offer of Guaranteed Debt Securities of the Debt Issuers as described in the Registration Statement on Form F-3 ("Registration Statement") filed by BP Group on or about the date of this letter under Rule 462(b) of the United States Securities Act of 1933, as amended ("Securities Act"). We confirm to you our opinion as set out in the Registration Statement under the caption "Taxation Considerations - Australian Taxation" in relation to matters of Australian tax law. We consent to the use of our name and the filing of this letter as an exhibit to the Registration Statement. In giving such consent, we do not admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act. Yours faithfully /s/ Mallesons Stephen Jaques