U.S. oil prices increased on Friday as a weaker greenback made the dollar-denominated oil more attractive for holders of other currencies.

The U.S. dollar slumped against other major peers on Friday after data showed the country's second quarter economic growth came in worse than expected.

The dollar index, which measures the greenback against six major peers, was down 1.17 percent at 95.603 in late trading.

Meanwhile, Brent crude prices extended losses on Friday as recent oil data intensified investors' fears on oversupply in the market.

The Energy Information Administration (EIA) said in its weekly report on Wednesday that U.S. oil inventories rose 1.7 million barrels last week to 521.1 million barrels, ending a 7-week streak of declines and beating market consensus of a 2.3-million barrels decrease.

The West Texas Intermediate for September delivery added 0.46 U.S. dollars to settle at 41.60 dollars a barrel on the New York Mercantile Exchange, while Brent crude for September delivery erased 0.24 dollars to close at 42.46 dollars a barrel on the London ICE Futures Exchange.