Updated from 11:41 a.m. EST

Crude oil prices closed at a new two-month low Tuesday as the November slump deepened.

The December futures contract was off 76 cents to $46.11 a barrel, near a two-month low. Prices are about 17% below their record high of $55.17 touched in late October.

U.S. production has been returning to normal following widespread disruption to operations in the Gulf of Mexico because of Hurricane Ivan in September.

Traders will get a better idea of current supply levels when key inventory data are released Wednesday morning. They'll also keep an eye on the situation in Nigeria, where the oil workers union has authorized a strike tomorrow.

Worries about short-term supply have dominated the market since the spring. Attacks on Iraq's oil infrastructure -- including the most recent one Sunday -- have caused periodic production problems of varying consequence there. Threats to production in Norway, Russia, Venezuela and Nigeria also have been a factor.