Offer for Alcan extended

Rio Tinto PLC
17 September 2007



Offer for Alcan extended to October 23, 2007

Rio Tinto Canada Holding Inc. ('RTCH') announces that the expiry date for the
offer by RTCH to acquire all of the common shares of Alcan Inc. is being
extended from September 24, 2007 to October 23, 2007.  The extension is
necessary to permit conditions to the offer to be satisfied, including obtaining
various regulatory approvals.  A formal notice of extension is being mailed
today to all Alcan common shareholders.



As of the close of business on September 14, 2007, 495,139 shares had been
deposited with the depositary under the offer and not withdrawn, representing
less than 0.2 per cent of Alcan's outstanding common shares on a fully-diluted
basis. The offer is conditional on acceptances representing 66 2/3 per cent of
Alcan shares.



About Rio Tinto



Rio Tinto is a leading international mining group headquartered in the UK,
combining Rio Tinto plc, a London listed company, and Rio Tinto Limited, which
is listed on the Australian Securities Exchange.



Rio Tinto's business is finding, mining, and processing mineral resources. Major
products are aluminium, copper, diamonds, energy (coal and uranium), gold,
industrial minerals (borax, titanium dioxide, salt, talc) and iron ore.
Activities span the world but are strongly represented in Australia and North
America with significant businesses in South America, Asia, Europe and southern
Africa.





For further information, please contact:

Media Relations, London                        Media Relations, Australia
Christina Mills                                Ian Head
Office: [phone]                   Office:  [phone]
Mobile: [phone]                   Mobile: [phone]


Nick Cobban                                    Amanda Buckley
Office:  [phone]                  Office:  [phone]
Mobile: [phone]                   Mobile: [phone]

Investor Relations, London                     Investor Relations, Australia
Nigel Jones                                    Dave Skinner
Office: [phone]                   Office:  [phone]
Mobile: [phone]                   Mobile: [phone]

                                               Investor Relations, North America
David Ovington                                 Jason Combes
Office:  [phone]                  Office:  [phone]
Mobile: [phone]                   Mobile: [phone]

Email: [e-mail]


Website: www.riotinto.com

High resolution photographs available at: www.newscast.co.uk







Additional information


The offer to purchase all of the issued and outstanding common shares of Alcan
for US$101 per common share in a recommended, all cash transaction (the 'Offer')
is being made by Rio Tinto Canada Holding Inc. (the 'Offeror'), an indirect
wholly-owned subsidiary of Rio Tinto. The Offer represents a total consideration
for Alcan common shares of approximately US$38.1 billion.



The Offer is open for acceptance until 6.00 p.m., Canadian Eastern Time, on
October 23, 2007, unless extended. The Offer is subject to a number of
conditions including valid acceptances by holders of not less than 66-2/3 per
cent of Alcan shares on a fully diluted basis and the receipt of various
governmental and regulatory approvals. The board of Rio Tinto has approved the
transaction.  The Offer is expected to close in the fourth quarter of 2007.



This announcement is for information purposes only and does not constitute or
form part of any offer or invitation to purchase, otherwise acquire, subscribe
for, sell, otherwise dispose of or issue, or any solicitation of any offer to
sell, otherwise dispose of, issue, purchase, otherwise acquire or subscribe for,
any security. The Offer (as the same may be varied or extended in accordance
with applicable law) is being made exclusively by means of, and subject to the
terms and conditions set out in, the offer and takeover bid circular delivered
to Alcan and filed with Canadian provincial securities regulators and the United
States Securities and Exchange Commission (the 'SEC') and mailed to Alcan
shareholders.


The release, publication or distribution of this announcement in certain
jurisdictions may be restricted by law and therefore persons in such
jurisdictions into which this announcement is released, published or distributed
should inform themselves about and observe such restrictions.



In connection with the Offer, an offer and takeover bid circular as well as
ancillary documents such as a letter of transmittal and a notice of guaranteed
delivery have been filed with the Canadian securities regulatory authorities and
the SEC and an Alcan directors' circular with respect to the Offer has also been
filed. A Tender Offer statement on Schedule TO (the 'Schedule TO') and a
Solicitation/Recommendation Statement on Schedule 14D-9 (the 'Schedule 14D-9')
has also been filed with the SEC.



SHAREHOLDERS OF ALCAN ARE URGED TO READ THE OFFER AND TAKEOVER BID CIRCULAR
(INCLUDING THE LETTER OF TRANSMITTAL AND NOTICE OF GUARANTEED DELIVERY), THE
SCHEDULE TO (INCLUDING THE OFFER AND TAKEOVER BID CIRCULAR, LETTER OF
TRANSMITTAL AND RELATED TENDER OFFER DOCUMENTS) AND THE SCHEDULE 14D-9 AS THEY
CONTAIN IMPORTANT INFORMATION ABOUT THE OFFER.



The offer and takeover bid circular as well as other materials filed with the
Canadian securities regulatory authorities are available electronically without
charge at www.sedar.com. The Schedule TO and the Schedule 14D-9 are available
electronically without charge at the SEC's website, www.sec.gov. Materials filed
with the SEC or the Canadian securities regulatory authorities may also be
obtained without charge at Rio Tinto's website, www.riotinto.com.



While the Offer is being made to all holders of Alcan common shares, this
announcement does not constitute an offer or a solicitation in any jurisdiction
in which such offer or solicitation is unlawful. The Offer is not being made in,
nor will deposits be accepted in, any jurisdiction in which the making or
acceptance thereof would not be in compliance with the laws of such
jurisdiction. However, the Offeror may, in its sole discretion, take such action
as it may deem necessary to extend the Offer in any such jurisdiction.



The Offer is made to holders in France of Alcan common shares admitted to
trading on Euronext-Paris. An announcement including the main information
relating to the Offer documents has been prepared and released pursuant to
article 231-24 of the AMF General Regulation and contains information relating
to how and in which time limit Alcan shareholders residing in France can accept
this Offer. The offer document and the announcement prepared pursuant to article
231-24 of the AMF General Regulation are available free of charge to the holders
of Alcan Shares registered with Euroclear France who request it from Citi
France, Global Transaction Services, Operations department, 19 le Parvis la
Defense 7, 92073 Paris la Defense. They are also available on the internet at
the following address: www.computershare.com/Rio-AlcanFrenchofferdocument.





The Offer is made to holders in Belgium of Alcan common shares and/or
certificates admitted to trading on Euronext Brussels (the 'IDRs'). A Belgian
supplement, addressing issues specific to holders of Alcan common shares and/or
IDRs in Belgium (the 'Belgian Supplement') was approved by the Belgian Banking,
Finance and Insurance Commission on 2 August 2007. The offer document and the
Belgian Supplement are available free of charge to the investors in Belgium who
request it from the Belgian branch of Citibank International plc, Department GTS
Operations, 4th floor, boulevard General Jacques 263G, 1050 Brussels. They are
also available on the internet at the following address: www.computershare.com/
Rio-AlcanBelgianofferdocument.




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