Weak fourth quarter reports from the energy sector helped sustain downward momentum sparked by China, leading to a lower opening Tuesday for crude oil prices.

British energy company BP reported more than $3 billion in losses for the fourth quarter, as lingering costs from the 2010 spill in the Gulf of Mexico add to pressures from the market downturn. Exxon Mobil was among the few companies of its kind reporting earnings for the fourth quarter, though revenues were sharply lower than fourth quarter 2014.

BP Chief Executive Bob Dudley said his company was taking a disciplined approach in preparation for an eventual rebound in the energy market.

"We are continuing to move rapidly to adapt and rebalance BP for the changing environment," he said in a statement.

Crude oil prices suffered a dramatic downturn at the start of trading Tuesday in New York. Brent crude oil prices moved lower by 5 percent to start the day at $32.54 per barrel. West Texas Intermediate, the U.S. benchmark price for crude oil, was down 4.1 percent from the previous close to open at $30.30 per barrel.

Oil prices rallied from mid-January lows of around $27 per barrel in part on speculation of potential production cut agreements from members of the Organization of Petroleum Exporting Countries and Russia, though prices have fallen in recent sessions after OPEC denied the validity of those rumors.

Iran, meanwhile, said it may add as much as 500,000 barrels of oil per day to an already-oversupplied market as sanctions pressures ease as the result of Tehran's commitment to a multilateral nuclear agreement brokered in July.

Brent is down more than 10 percent for the year.

The year started on a low note amid fresh concerns about the pace of economic growth in China. Those concerns carried into February after Beijing reported manufacturing activity was at historic lows.

Lower oil prices are starving exporting nations like Saudi Arabia and Russia of revenue. In the United States, top oil producer Oklahoma said it may be facing a $1 million budget gap because of lingering weakness in the energy sector.