Updated from 2:34 p.m. EDT

For oil traders, the fourth time was the charm.

Crude oil prices Friday closed above $50 a barrel, after failing to hold the psychologically-important level the three previous sessions.

Based on final figures, the November futures contract added 48 cents to $50.12 in regular floor trading on the New York Mercantile Exchange. The intraday high was $50.13.

The new record high surpasses those set on Monday and Tuesday. Prices are up about 14% in the past three weeks.

Traders have been worried about short-term supplies during a period of unusually strong global demand. U.S. production in the Gulf of Mexico is still recovering from disruptions from Hurricane Ivan, while civil unrest in Nigeria has caused temporary cutbacks there as well. The government there is holding talks with leaders of a rebel group in the Niger River delta, the main source of the African nation's abundant oil reserves.

Earlier this week, two closely watched reports showing an unexpected increase in U.S. crude inventories in the latest week broke a nine-session run-up.

Market sentiment remains largely bullish despite efforts by OPEC to keep a lid on prices. Saudi Arabia Tuesday said it would boost its official production capacity by 1.5 million barrels to 11 million barrels a day.

The move by the world's largest oil exporter follows OPEC's decision two weeks ago to increase its official production ceiling for the third time in three months. The cartel said it was raising output by 1 million barrels a day, after boosting production by a combined 2.5 million barrels in July and August.