Oil prices ended slightly lower Friday on profit-taking after recent solid gains.

U.S. oil surged about 20 percent in April, the largest monthly gain in a year, helped by a weaker U.S. dollar and reduced U.S. crude output. Traders were looking for excuses to lock in profit after recent solid gains.

The rising oil production from the Organization of Petroleum Exporting Countries (OPEC) members also weighed on investor sentiment. A Bloomberg survey showed that the OPEC boosted output by 484,000 barrels to 33,217 million a day in April.

Meanwhile, the active U.S. rigs count of this week fell by 11 to 332, continuing losses into a sixth week, oilfield services company Baker Hughes said Friday.

The West Texas Intermediate for June delivery fell 11 cents to settle at 45.92 U.S. dollars a barrel on the New York Mercantile Exchange, while Brent crude for June delivery decreased 1 cent to close at 48.13 dollars a barrel on the London ICE Futures Exchange.