Crude oil prices started the trading day Wednesday relatively flat as concerns about an oversupplied market were offset by declines in the U.S. economy.

Brent crude prices lost about one-half of 1 percent in early Wednesday trading to sell for $64.45 per barrel. West Texas Intermediate, the U.S. benchmark, lost about six-tenths of a percent to $60.65 per barrel.

Market momentum early Wednesday was driven by a report from the American Petroleum Institute that suggested domestic crude oil inventories declined for the eighth consecutive week, indicating demand may be growing in the U.S. economy.

Data on U.S. claims for unemployment insurance continue to show improvements in the labor market. Federal Reserve Chairwoman Janet Yellen warned in May, however, the U.S. economy was still facing headwinds.

The U.S. Commerce Department said Wednesday the domestic economy was still struggling to emerge fully from contraction.

"Real gross domestic product decreased 0.2 percent in the first quarter of 2015, in contrast to an increase of 2.2 percent in the fourth quarter of 2014," it said.

That's better than the 0.7 percent dip reported by the Commerce Department last month, suggesting the U.S. economy is on a slow road to recovery.

Crude oil prices started Tuesday in negative territory, but rallied amid concerns over potential delays in an Iranian nuclear deal. Iranian Supreme Leader Ali Khamenei said in a late Tuesday speech there would be no commitments on a nuclear drawdown unless sanctions are "lifted immediately."