The emergency oil loan comes as U.S. oil prices CLc1> rose to settle at $50.12 a barrel last week, the first time the benchmark contract has closed above $50 in its 21 years of trade on the New York Mercantile Exchange. Oil prices have jumped 50 percent since the beginning of the year.

Oil companies have turned to the government for help, asking it to dip into the 670-million-barrel Strategic Petroleum Reserve.

Astra Oil was granted a 1 million barrel loan from the emergency stockpile, becoming the fourth company in a week to receive such relief.

Astra is a subsidiary of Transcor, which is controlled by Belgian businessman Albert Frere, whose vast holdings include a stake in French oil company Total (TOTF.PA: Quote, Profile, Research) .

The department has now loaned a total of 4.2 million barrels of the reserve's oil

Besides Astra, oil loans were also provided to Shell Oil (RD.AS: Quote, Profile, Research) (SHEL.L: Quote, Profile, Research) , ConocoPhillips (COP.N: Quote, Profile, Research) and privately held Placid Refining.

Astra's oil will be delivered to the Crown Central Petroleum refinery in Pasadena, Texas, Energy Department spokeswoman Jeanne Lopatto said.

Astra, based in Huntington Beach, California, will be receiving so-called "sweet" crude from the reserve, because it is easier to process into petroleum products than heavier grades of crude.

The oil will be delivered to the refinery in October "in batches to be determined by Astra," Lopatto said. The crude shipments will begin flowing next week.

The spokeswoman would not say if the department is still considering oil loan requests from other companies. "We will continue to review requests and act on them if it's appropriate," she said.

The emergency reserve was created by Congress in the mid- 1970s after the Arab oil embargo, and holds its crude in underground salt caverns at four sites in Texas and Louisiana.