EXHIBIT 8.1

                     [Letterhead of Sullivan & Cromwell LLP]

                                                                          , 2003

Alcan Inc.
1188 Sherbrooke Street West
Montreal, Quebec, Canada H3A 3G2


Dear Sirs:

            We have acted as your United States federal income tax and French
income tax counsel in connection with the registration under the Securities Act
of 1933 (the "Act") for the purpose of exchanging Pechiney Common Shares,
Pechiney Bonus Allocation Rights, Pechiney OCEANEs and Pechiney ADSs for Alcan
Common Shares and/or cash. We hereby confirm to you that our opinion is as set
forth under the caption "Taxation" with respect to United States federal income
taxation and French taxation in the prospectus dated -, 2003 (the "Prospectus"),
included in the related Registration Statement on Form S-4 filed by the Company
with the Securities and Exchange Commission (the "Registration Statement"),
subject to the limitations set forth therein.

            We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to us under the heading "Taxation"
in the Prospectus. 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 Act.

                                    Very truly yours,