Updated from 11:26 a.m. EST

Crude oil prices closed sharply lower Monday after a double-digit surge last week, with traders trying to assess the outcome of the auction of Yukos' Siberian production unit Sunday.

The January futures contract, which expired at the end of trading today, was off 64 cents to $45.64 on the Nymex.

After a deep two-month correction, prices soared last week amid unseasonably cold weather and the heightening drama surrounding the future of the Russian oil giant.

The Russian government Sunday capped a months-long tax battle with Yukos management by auctioning off its highly profitable Siberian production unit, Yuganskneftegaz.

The auction was won by the previously unknown Baikal Finans Group with a $9.3 billion bid, according to reports.

In a last-ditch effort to hold off the auction, Yukos management last week filed for Chapter 11 bankruptcy protection in the U.S. and later obtained a restraining order against the sale. The legal maneuver -- of dubious international merit -- ultimately failed.

According to various accounts, Moscow says Yukos owed some $28 billion in back taxes.

Traders Monday were monitoring events in the Middle East after a message by al Qaeda leader Osama bin Laden urged militants to strike Saudi Arabian oil facilities, according to media reports.

Worries about terrorism, along with periodic disruptions to Iraq's production from sabotage, have been among the many factors supporting oil prices this year. Prices hit a record closing high of $55.17 on Oct. 26 before undergoing a steep correction.