Oil prices fell on Monday as Saudi Arabia said it was pumping more oil, exacerbating a global supply glut, analysts said.
US benchmark West Texas Intermediate for delivery in May fell 37 cents to $46.20 a barrel compared with Friday's close.
Brent North Sea crude for May dipped five cents to stand at $55.28 a barrel in London midday deals.
"Selling pressure was generated in particular by statements made at the weekend by the Saudi Arabian oil minister," said Commerzbank analyst Carsten Fritsch.
Bloomberg News quoted Saudi Arabia's oil minister Ali al-Naimi as saying on Sunday that his country is producing almost 10 million barrels of crude a day.
Saudi Arabia, the main producer in the Organization of the Petroleum Exporting Countries, pumped 9.85 million barrels a day in February, according to Bloomberg.
He meanwhile has called on oil producers outside OPEC to help boost falling crude prices as the cartel refuses to take responsibility alone.
"We refuse to take responsibility alone because (OPEC) produces 30 percent of market output and 70 percent comes from outside," Naimi said in remarks carried Monday by the Saudi Press Agency (SPA).
New York prices slumped by about 60 percent between June and February, weighed down by a glut of global supplies and concerns about stalling demand.
The slide was exacerbated in November when OPEC refused to cut production to rescue falling prices, with analysts saying the cartel wanted to maintain its market share amid surging US output.
Crude futures had won a boost Friday from another fall in the dollar and market adjustment at the end of the April contract for WTI, analysts said.
The US benchmark West Texas Intermediate for delivery in April had added $1.76 to $45.72 a barrel in New York trade.