Rio Tinto issues warning on Tweed offer

Rio Tinto, the world's third largest mining company, has warned its shareholders to be wary about potential unsolicited offers from sharemarket opportunist David Tweed.

Rio Tinto said it was aware that a company called Australian Share Purchasing Corporation Pty Ltd, of which Mr Tweed was the sole director, had written to some shareholders offering to purchase their shares.

Rio Tinto said that on April 30, some shareholders were offered A$100 for each Rio Tinto share at a time when the average price in the last week of April was A$142.91.

Tweed in the past has made offers to shareholders in AXA Asia Pacific and Tower Australia.