BHP Billiton is in talks with Royal Dutch Shell on buying its 24.3% stake in Australia's Woodside Petroleum and the sides have been holding detailed discussions about a potential deal, the Australian Financial Review said on Monday without citing its sources.

However, it remained unclear if and when a deal could be concluded on Shell's Woodside stake, currently worth A$9.1 billion, with Shell saying it was not in a hurry to do anything, the paper said.

Talk of takeover interest, including from BHP, sharply lifted Woodside shares late last month but at the time the company said it was not aware of information that would account for the price surge and it would not comment on rumors.

Talk of a BHP bid picked up steam last November when Shell sold a third of its stake in Woodside and said it would be willing to sell the remaining 24%.

BHP has plenty of cash to put to work after enjoying a boom in commodity prices and failing in its $39 billion bid for Canada's Potash Corp.