Big oil firms struggle to find new reserves

Big U.S. oil firms more than matched the oil and gas they pumped last year with new finds, while European rivals failed to do so, but the underlying performance of both reinforced fears the industry is short of attractive exploration opportunities.

U.S. oil firms mainly relied on acquisitions to achieve large reserves additions in 2005, and Europeans may have to follow their lead in future if they want to halt an erosion of their asset bases.