London, Jun 21 (AFP) World oil prices retreated today as traders eyed a deepening Greek debt crisis and resurgent worries about the Chinese and US economies, analysts said.

In early trade, New York's main contract, West Texas Intermediate (WTI) light sweet crude for July delivery, plunged to USD 91.14 a barrel -- the lowest point since February 23.

The July contract, which expires at the end of trading today, later recovered to USD 92.80 a barrel, down 21 cents from Friday's close.

Elsewhere today, Brent North Sea crude for August shed 94 cents to USD 112.27 a barrel in late London deals.

"Crude oil prices extended (pre-weekend) losses, dragged lower by persistent concerns about Greece," said analyst Myrto Sokou at the Sucden Financial Research brokerage.

"The euro reacted straight on the news and came under further pressure against the US dollar, weighting heavily on most commodity prices and pushing oil prices lower.