Oil prices fell on Thursday, extending losses from the previous day, pressured by large builds in U.S. fuel inventories last week, though concerns over tighter supplies from OPEC members and Russia capped the decline. Both benchmarks lost more than 1% on Wednesday, as a stronger dollar and a bigger-than-expected rise in U.S. fuel stockpiles weighed on prices. Gasoline stocks rose by 6.3 million barrels last week to 237.7 million barrels, the U.S. Energy Information Administration said on Wednesday.