Rio Tinto, the world's second-biggest miner, is drawing up plans to gatecrash Alcoa Inc's $28 billion hostile bid for North American rival Alcan Inc., the Daily Telegraph said on Friday.

The newspaper, without citing sources, said Rio had engaged Credit Suisse and Deutsche Bank to advise it on a range of options, including a possible bid for Alcan. A bid for Alcoa was also possible, but less likely, it added.

Rio declined to comment.

Alcan is the world's third-largest maker of primary aluminium, behind Alcoa and Russia's Rusal. An Alcoa-Alcan link-up, or an Alcan-Rio combination would top Rusal.

If Rio buys Alcan, it would have access to two of the world's largest deposits of bauxite -- Rio's existing Weipa deposit and Alcan's Gove deposit, both in Australia. Bauxite is required to make alumina, then aluminium, which is used in products ranging from drinks cans to airplanes.

Earlier this week, Rio announced plans to invest $1.8 billion in expanding its alumina refining operations, which some analysts interpreted as a sign it would not bid for Alcan.

Alcoa made its bid for Alcan on May 7, about six months after two years of merger talks with Alcan collapsed. The bid of $58.60 cash and 0.4108 Alcoa shares for each Alcan share expires July 10, but the U.S. company expects to extend it.

BHP Billiton Ltd. Plc., Norsk Hydro ASA, Companhia Vale do Rio Doce, Rusal, Anglo American and Xstrata Plc. are also viewed by analysts as potential bidders for Alcan.

Montreal-based Alcan, split off from Alcoa in the 1920s because of antitrust concerns, is expected to unveil its own strategy in the coming weeks, indicating whether it wants to remain independent, find another suitor, or reach a friendly deal with Alcoa.

(additional reporting by James Regan in Sydney)