Oil prices were under pressure on Monday as a rebound in Libyan oil output at the weekend weighed against upbeat economic data from Asia that pointed to strong energy demand from the region.
Benchmark Brent futures fell by 41 cents to $53.12 a barrel.
U.S. West Texas Intermediate crude futures closed down 36 cents at $50.24 a barrel.
Libya's Sharara oil field, the country's largest, resumed production on Sunday after a week-long disruption. State-owned NOC lifted force majeure on loadings of Sharara crude on Monday, sources told Reuters.