new york (ap)

Oil prices dipped in volatile trading Monday, after election-related violence in oil-producing Nigeria failed to sustain a rally.

Light, sweet crude for May delivery slipped 2 cents to settle at $63.61 per barrel on the New York Mercantile Exchange. Earlier, prices climbed as high as $64.21 and fell as low as $62.55.

Brent crude for June fell $1.38 to $67.25 a barrel on London's ICE Futures Exchange.

Citigroup Global Markets energy analyst Tim Evans said prices rose overnight after at least 21 people died in Nigeria in election-related violence, but the rally fizzled. Nigeria is the world's eighth-largest exporter and a main supplier of oil to the United States.

"There's a sense in the ongoing market that when it fails to rally on bullish news, that all by itself is reason to sell," Evans said. "I'm not saying that's right, but that's the psychology of the market."

Forecasts for warmer U.S. weather also helped to ease oil, natural gas and heating oil prices, Evans said.

Alaron Trading Corp. commodities broker David Beavers said falling gasoline prices also helped to drag down crude. Gasoline has been the strongest performer in the oil complex and helped to lead crude up in recent weeks.

"From the trader's perspective, there isn't any compelling reason to break recent highs, and they're more inclined to take profits," Beavers said.

Gasoline futures fell 6.4 cents to $2.1157 per gallon on the Nymex.

Prices rose last week due to problems at several U.S. refineries and a decrease in U.S. gasoline stockpiles. Some refineries are expected to resume gasoline production this week, which should help to draw down crude inventories.

"We will not know that refinery snag contagion has ended, it ends," said John Kilduff at Fimat USA.

Gasoline supplies sank during the first week of April amid strong demand and lower production, with stockpiles down 5.5 million barrels to 199.7 million barrels, the U.S. Energy Information Administration reported Wednesday.

In other Nymex trading, heating oil futures fell 4.14 cents to $1.8593 a gallon, while natural gas prices slipped 27.1 cents to $7.53 per 1,000 cubic feet.