Oil rises 4.6 percent on Nigeria, U.S. refinery fire

NEW YORK (Reuters) - Oil prices rose 4.6 percent on Monday as violence in Africa's top crude exporter Nigeria and a fire at a key U.S. East Coast refinery revived concern about supplies.

Strength on Wall Street and weakness in the U.S. dollar Monday encouraged buying on the oil market, dealers said.

U.S. crude for June rose $2.58 to $58.92 by 1720 GMT, while London Brent for July rose $2.48 to $58.46.

The gains came after Nigerian militants said they had blown up two oil and gas pipelines in the Niger Delta and would blockade waterways in the region in an effort to disrupt energy exports from the OPEC country.

Unrest in the world's 12th largest oil producer routinely impacts output levels.

In the United States, an explosion rocked Sunoco's oil refinery in Marcus Hook, Pennsylvania, sparking off a fire and disrupting production from the 178,000-barrel-per-day plant heading into peak summer driving season.

"The Nigerian stories probably would not have much of an impact on their own, but combined with the refinery glitches are contributing to a positive start to the week," said Tony Machacek, a broker at Bache Commodities.

Machacek added that a weaker U.S. dollar and early gains in equity markets was adding to oil's gains.

U.S. stocks rose on light volume on Monday as a better-than-expected quarterly profit and upbeat outlook from Lowe's Cos Inc, the No. 2 U.S. home improvement retailer, fueled hopes the economic slump was easing and spending was stabilizing.