Oil prices collapsed on Thursday to their lowest since late November as investor worries about the world's stubbornly persistent glut of crude erased most of the gains that followed last year's OPEC's output cut. The slide worsened after OPEC delegates downplayed the chance that their group and other producing countries would deepen their output cuts when they meet on May 25. They did say current output cuts were likely to be extended. U.S. West Texas Intermediate (WTI) crude futures ended trading down $2.30, or 4.8 percent, at $45.52 a barrel. Brent crude oil futures were down $2.53, or 5 percent, at $48.26 a barrel by 2:53 p.m. (1853 GMT). Both contracts slid during the session to the lowest since Nov. 30, the day OPEC agreed to cut supply. They were on track for their biggest daily percentage declines March 8.

A laborer works at the Nahr Bin Umar oil field, southeast of Baghdad, Iraq. Essam Al-Sudani | Reuters

"The market continues to hunt for a bottom," said Gene McGillian, manager of market research at Tradition Energy in Stamford, Connecticut. Late last year, the Organization of the Petroleum Exporting Countries and other producing countries announced oil output cuts of 1.8 million barrels per day (bpd) for the first six months of this year. Even so, McGillian said, "We still have a near record overhang and signs of increasing production in areas of the world outside the producers that agreed to the cuts." Crude output has surged in the United States, with increasing rig counts for the past 11 months. Weekly U.S. government data on Wednesday showed crude stocks fell 930,000 barrels, less than half the 2.3 million barrel drop analysts had expected. Stocks stand just 7 million barrels off a record high. U.S. gasoline futures were down nearly 4 percent after the stockpile report indicated continued weakness in gas demand. They are have fallen more than 8 percent this year. OPEC oil output fell for a fourth straight month in April, a Reuters survey found on Tuesday, as top exporter Saudi Arabia kept production below its target, which helped offset weaker compliance by other members.