BHP quiet on Alcan, Alcoa speculation

BHP Billiton has declined to comment on whether it is considering a takeover bid for either Alcan or Alcoa.

A report by Reuters last night said the world's biggest miner had hired investment bank Merrill Lynch & Co to explore the possibility of buying aluminium producer Alcan.

And in a separate story, The Times newspaper in London said BHP was reviving plans to have a tilt at Alcoa, which is also an aluminium producer.

"We don't comment on market speculation," a BHP spokesperson told AAP this morning.

Alcoa has already launched a hostile $US28.7 billion ($34.15 billion) takeover bid for Alcan.