Chevron Corp said on Thursday its refining and marketing arm would return to profit in the first quarter as refining margins improved, while earnings from oil and gas production would continue to grow.

Shares of the second-largest U.S. oil company rose nearly 0.5 percent in after-hours trading to $78.00, after gaining 0.4 percent in regular Thursday trade.

Chevron said global oil and gas production of 2.76 million barrels per day (bpd) in the first two months of the quarter was weaker than the quarter before, but improved oil prices would drive upstream earnings growth.

Its U.S. oil-equivalent output in January and February was down 20,000 bpd from the previous quarter at 731,000 bpd, while international output grew by 5,000 bpd in the first two months of the quarter to 2.032 million bpd.

Chevron, which aims to achieve average 2010 output of 2.73 million bpd, said the decline in production was largely in the Gulf of Mexico, reflecting the absence of a royalty settlement recognized in the previous quarter.

But benchmark U.S. oil prices averaged nearly $79 in the first quarter, about $3 above the quarter before and sharply higher than the $43 average of the first quarter of 2009.

(Reporting by Braden Reddall, editing by Matthew Lewis)