Among its many assets, Anglo owns five coal operations in Queensland and two in New South Wales.

London-based publication The Observer said yesterday, quoting sources in the City, that Anglo was worth $US60 billion ($A79 billion) but any bidder would have to pay a bid premium, potentially boosting the full cost up to $80 billion.

Xstrata, Rio and CVRD are rumoured to have hired financial advisers to look at the possible break-up of Anglo.

Xstrata's takeover battle for copper and nickel company, Falconbridge, and CVRD's pursuit of metals company Inco were cited as signs of their appetite for mining assets.

An investment banker told the The Observer that “Anglo has been shedding businesses to streamline its operations, but many investors would like it to go on the front foot and buy assets that are being snapped up by its competitors. If it doesn't, it could find itself prey rather than predator, and someone else could break it up.”