HOUSTON — Exactly one year after crude eclipsed $100 a barrel for the first time, 2009 trading began today with prices roughly half their year-ago levels, and some believe oil could be headed even lower.

Oil markets kicked off the new year with crude climbing to about $46 a barrel. A variety of factors were likely at work, including expectations that OPEC would carry out its largest production cut ever to stem the historic price decline and violence in Gaza.

Oil's surge into triple digits for the first time one year ago was the start of a climb that would peak above $147 a barrel by July. Since then, amid fears of a prolonged global recession and crumbling worldwide demand, crude prices have plunged more than 70 percent.

Gasoline prices ticked up a bit overnight, but the average price for a gallon of unleaded is still more than $1.40 cheaper than a year ago.

A weakened manufacturing sector suggests demand for energy will not rebound any time soon.