Chevron Corp. (CVX), the nation's second-largest oil company, said its third-quarter profit climbed 12 percent, but would have been much higher if not for production losses caused by hurricanes and other storms that damaged its Gulf of Mexico operations.

The San Ramon-based company said Friday it earned $3.6 billion, or $1.64 per share, during the three months ended in September. That compared with net income of $3.2 billion, or $1.51 share, in the same quarter last year.

Revenue for the period totaled $54.5 billion, a 34 percent increase from $40.7 billion last year.

The results were well below the consensus earnings estimate of $1.91 per share among analysts surveyed by Thomson Financial. But that figure did not include the earnings erosion caused by the Gulf of Mexico (search) storms.

Chevron estimated its profit would have been at least $600 million higher if not for the problems caused by Hurricane Katrina (search), Hurricane Rita and a series of small storms during the quarter. A $600 million profit loss translates into about 27 cents per share, meaning the company might have matched the analysts' estimate if not for the storms.

Chevron also warned the fallout from the Gulf of Mexico storms will have an even larger impact on its fourth quarter earnings.

On the flip side, Chevron's profit was bolstered by its August acquisition of Unocal Corp., but that was not enough to make up for the financial blow delivered by the hurricanes, said Chairman David O'Reilly.

"These storms reduced our crude oil and natural gas production in the third quarter by about 90,000 barrels of oil-equivalent per day," he said in a statement. "And our refinery in Pascagoula, Miss., had to be shut down on two separate occasions for a total of about 90 days.

The Mississippi refinery, which has a capacity to produce up to 325,000 barrels per days, restarted earlier this month.

Last month, Chevron had warned its third-quarter profit would be at least $350 million lower than expected, primarily because of Hurricane Katrina.

Shares of Chevron fell 86 cents, or 1.5 percent, to $55.64 on the New York Stock Exchange. The stock has traded in a 52-week range between $49.81 and $65.98.