SPOKANE, Wash. (AP) _ While striking workers picketed outside Thursday, officials of Kaiser Aluminum Corp. tried to keep five plants running with managers, replacement workers and retirees.

No talks were scheduled in the dispute over job security, benefits and pay at the nation's fifth-largest aluminum manufacturer.

Round-the-clock picketing was under way at plants in Washington, Louisiana and Ohio. The walkout affects more than 3,000 workers.

Businesses in the Spokane area, where Kaiser employs more than 2,100 hourly workers, were bracing for an economic hit from the strike that began Wednesday evening.

Strikers, meanwhile, questioned whether replacement workers could operate the machinery involved in aluminum production.

``It's hot and gassy and dangerous work,'' said striker Tim Charbonneau of United Steelworkers Local 329 at the Trentwood mill near Spokane. ``You can't just take somebody off the street to do it.''

Kaiser spokeswoman Susan Ashe said the plants were still producing aluminum and planned to do so ``indefinitely'' to meet their customer commitments.

The Trentwood plant makes aluminum components for jetliners, automobiles, and for soft drink cans.

Several workers said they were prepared to weather a long strike, in part because the Steelworkers have a $200 million strike fund.

The company's last contract offer Wednesday called for laying off some 400 workers at its five plants, and transferring more work to outside sources. The five-year contract proposal also called for a total pay increase of $2.75 per hour, and some benefit and pension improvements.

Kaiser President Ray Milchovich said the offer would allow the company flexibility to compete with larger aluminum makers.

But union leaders demanded that their pay and benefits equal those of larger companies. They also objected to the layoffs and the outsourcing of work.

The union contends Kaiser's wages and benefits are below industry averages because workers agreed to pay and pension givebacks to help the company weather financial rough spots in the 1980s.

Both sides indicated they were open to resuming negotiations that began Sept. 1.

The contract that expired Wednesday was ratified after a nine-day strike in 1995.