Rio Tinto offer for Alcan – additional shares acquired

Rio Tinto today announces that approximately 9,764,000 additional common shares of Alcan
Inc. (“Alcan”) have either been validly deposited and taken up under the offer by Rio Tinto
Canada Holding Inc. (“RTCH”) to acquire all of the shares of Alcan (the “Offer”) or are
covered by notices of guaranteed delivery. These additional shares (which represent
approximately 2.60 per cent of the outstanding shares), together with approximately
350,667,000 shares already beneficially owned by RTCH, represent approximately 95.82 per
cent of the outstanding shares of Alcan.

RTCH is now entitled to acquire all the remaining Alcan shares by way of compulsory
acquisition under the Canada Business Corporations Act. RTCH will exercise these rights
promptly after the expiry of the Offer.

All additional validly deposited shares during the balance of the Offer period will be taken up daily and payment for such shares will be made to the depositary within two business days
of take-up. Shares covered by notices of guaranteed delivery will be taken up when the
certificates representing them are delivered to the depositary. The Offer expires at 6:00 p.m.
(Canadian Eastern Time) on November 8, 2007.