* U.S. crude stocks up 2.9 mln barrels last week - API * Saudi Arabia raises monthly prices for crude sales * Fighting escalates in Libya, militants seize oilfield * Coming up: EIA weekly oil inventories data at 1530 GMT (Updates prices, adds Libya detail, previous dateline SINGAPORE) By David Sheppard LONDON, March 4 (Reuters) - Brent dipped on Wednesday but held above $60 a barrel, supported by a rise in Saudi crude prices and air strikes and militant raids on oil facilities in Libya. In a move widely seen as showing Saudi Arabia's confidence in a demand recovery, the OPEC kingpin raised official selling prices (OSPs) for its oil deliveries to Asia and the United States on Tuesday. "This is a sign that prices have bottomed out because it means Saudi is confident in raising prices without being afraid of losing market share," said Tony Nunan, a risk manager at Mitsubishi Corp in Tokyo.