Mining giant BHP Billiton plans to use part of a cash surplus of around U.S.$18 billion to fund a round of acquisitions, possibly involving some large rivals, The Wall Street Journal reported.

The newspaper quoted BHP's Chief Commercial Officer Alberto Calderon as saying four or five opportunities had been identified, all involving assets in the mining and energy sectors.

Around $10 billion had been set aside for development of existing projects and initiating new ones in the current fiscal year, which ends in June 2010, Calderon said. A separate undisclosed amount had been set aside for acquisitions.

We have no pressure to do it. But I can tell you we have done a lot of work, Calderon was quoted as saying in a report from London.

The Anglo-Australian mining giant is the world's largest mining company and last year withdrew from a bid to acquire one of its largest rivals, fellow Anglo-Australian miner Rio Tinto, after the two failed to agree on price.

Calderon said the company wanted to put its balance sheet to work amid globally low prices due to the economic downturn. The company was seeking to expand in specific areas, naming them as iron ore, copper, coking coal, petroleum and potash, he said.

(Editing by Dean Yates)