Oct. 27 (Bloomberg) -- Valero Energy Corp., the largest U.S. refiner, said it will shut its Delaware refinery in November for repairs and its Norco, Louisiana, plant in January for planned work.

“It’s more cost-effective” to shut a refinery when repairing major processing units, Bill Day, a company spokesman, said in an interview. Four other refineries will undergo planned repairs, Day said in releasing a maintenance schedule for the fourth quarter and the first quarter of 2010.

The Delaware refinery will shut in November for 52 days to repair the 81,000-barrel-a-day fluid catalytic cracker and alkylation unit. The plant shut a coker and gasifier this month and is cutting jobs as Valero seeks strategic alternatives for the money-losing operation, including a possible sale.

“When margins continue to be very poor and you’re going to do maintenance on the units in a refinery that are the most profitable, it makes little sense to keep the rest of the place running,” said Andy Lipow, president of Lipow Oil Associates LLC in Houston.

The reliability of the Delaware refinery was compromised by ongoing issues with the gasifier, Chief Executive Officer Bill Klesse said during an earnings conference call. “As we get the cat cracker fixed, we’ll see how we look next spring. I expect economics to look a lot better.”

No Delaware Restart Soon

The Delaware fluid coker won’t restart soon because the economics haven’t improved enough, Chief Operating Officer Richard Marcogliese said during the earnings call. Once the restart decision is made, it will take about two months to prepare to run feedstocks through the unit, he said.

Valero today reported it lost $489 million, or 87 cents a share, in the third quarter as fuel demand slumped. The loss was the third in four quarters.

The St. Charles refinery in Louisiana will be closed in January for 36 days for repairs to a 190,000-barrel-a-day crude unit and a coker. The coker has been running at reduced rates because of poor margins.

Maintenance Plans

Valero plans to idle units at four other plants for maintenance.

The company will shut a 56,000-barrel-a-day fluid catalytic cracker and alkylation unit at the Wilmington, California, plant in November for 39 days. The Delaware repairs and the work at Wilmington were accelerated to the fourth quarter from the first quarter, Chief Financial Officer Michael Ciskowski said during the company’s earnings conference call today.

Similar units at Port Arthur, Texas, will go down for 44 days beginning in January. The Port Arthur plant will also shut a 45,000-barrel-a-day hydrocracker in March for 38 days.

Valero’s Corpus Christi, Texas, two-plant complex will idle two hydrocrackers, one in January for 18 days and the second in February for 18 days.

The Memphis refinery will perform maintenance on a 105,000- barrel-a-day crude unit, a fluid catalytic cracker and an alkylation unit in March for 45 days.

To contact the reporter on this story: Barbara Powell in Dallas at bpowell4@bloomberg.net

Last Updated: October 27, 2009 12:31 EDT