Chevron Corp.'s (CVX) third-quarter earnings fell 33%, reflecting a sharp drop in downstream earnings and lower production.

"This quarter's earnings were solid, but off from their near record level of a year ago," said Chairman and Chief Executive John Watson. "Crude oil prices were down and we had a heavy period of planned oil field maintenance, which temporarily reduced oil and gas production in several locations. Foreign currency movements also hurt our results this quarter, while they benefited the year-ago period."

Last month, Chevron warned its third-quarter profit would fall substantially from the previous quarter, after Hurricane Isaac affected its oil production. The company had said foreign exchange losses as well as lower production would hurt its exploration-and-production business. Meanwhile results from its refining, marketing and chemical operations would decline significantly, due in part to the early August shutdown of a California refinery after a fire.

Chevron is the second-largest U.S. oil company by market value after Exxon Mobil Corp. (XOM). On Thursday, its larger rival reported its third-quarter earnings fell 7.4% as its production slid to the lowest level in three years and revenue decreased 7.7%.

Chevron reported a profit of $5.25 billion, or $2.69 a share, down from $7.83 billion, or $3.92 a share, a year earlier. Revenue fell 9.9% to $58 billion.

Analysts polled by Thomson Reuters had most recently forecast earnings of $2.83 a share on revenue of $63.9 billion.

Exploration-and-production earnings fell 17% to $5.14 billion.

The refining, marketing and chemical operations, known as the downstream segment, posted a profit drop of 65% to $689 million.

Total oil-equivalent production decreased 3.1% to 2.52 million barrels per day. But Chevron said it expects production in the fourth quarter to increase from the third quarter, reflecting the completion of planned turnarounds and restoration of shut-in production in the Gulf of Mexico.

Shares closed Thursday at $111.46 and were inactive premarket. The stock has risen 4.8% so far this year.