Exhibit 8.3

                    [LETTERHEAD OF BP CANADA ENERGY COMPANY]

November 3, 2003

BP Canada Finance Company
240 - 4th Avenue, S.W.
Calgary, Alberta
T2P 4H4

Ladies and Gentlemen:

In connection with the registration under the Securities Act of 1933, as amended
(the "Act"), pursuant to a shelf registration statement on Form F-3 (the
"Registration Statement") of guaranteed debt securities (the "Securities") of BP
Canada Finance Company, a Nova Scotia company (the "Company"), I have, as
counsel to the Company, examined such corporate records, certificates and other
documents and considered such questions of law as I have considered necessary or
appropriate for the purposes of this opinion. In particular, I have relied on
the advice of BP Canada Energy Company's tax department.

I have reviewed the subsection in the Registration Statement under the caption
"Tax Considerations - Canadian Taxation" and hereby confirm that it is my
opinion that the disclosure under such subsection is accurate as to matters of
Canadian income tax law.

This opinion is limited to the laws of the Province of Alberta and the laws of
Canada applicable therein and I do not express any opinion herein concerning the
laws of any other jurisdiction.

I hereby consent to the filing of this opinion as an exhibit to the Registration
Statement. In giving such consent, I do not admit that I am within the category
of person whose consent is required under Section 7 of the Act.

Yours truly,

BP CANADA ENERGY COMPANY

  /s/ Francine Swanson
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Francine Swanson, Q.C.
Senior Legal Counsel
BP Canada Energy Company