Crude oil futures ended with gains on Thursday as speculation rose that a renewed strike in Nigeria may curb supplies.

Strike threats arose at a Chevron unit in Nigeria after a senior union of oil workers said talks to stave off a work stoppage were not doing well.

Nigeria is Africa's top oil producer and the country is a large supplier to the United States.

Crude oil futures for July delivery rose 37 cents or 0.27 percent to $136.75 a barrel at 3:38 p.m. in New York. Prices hit an all time record of $139.12 a barrel on June 6.

On Wednesday, crude soared $5.07 or 3.9 percent to $136.38 a barrel after the U.S. Energy Department released its inventories report.

The Energy Department reported yesterday that U.S. gasoline supplies increased by 998,000 barrels last week, while U.S. crude supplies fell 4.56 million barrels to 302.2 million last week and distillate stockpiles rose by 2.3 million barrels.

Brent crude futures for July delivery rose $1.89 or 1.41 percent to $136.52 a barrel on the London ICE Futures Exchange. Brent prices climbed to a record $138.12 in June 6.

Earlier crude declined as the dollar had gains against the euro and yen after U.S. retail sales showed better than expected data rising 1 percent in May, the most in six months. The euro fell 0.82 percent against the dollar and was trading at $1.5422 by 3:53 p.m. today.

The dollar is driving the market again, said Phil Flynn senior trader at Alaron Trading Corp. in Chicago in an e-mailed statement today. The dollar also gained against the yen.