Washington — As if your 401(k) hadn't been through enough.

American workers, forced to look on helplessly as the value of their 401(k)s sink in sync with the Dow, now have something else to worry about. Last week, General Motors told its nonunion employees that starting next month, it would stop matching their contributions to their 401(k) plans until business conditions improve.

The move by the largest of the Detroit automakers reverberated well outside the auto industry. It raises the specter that the economic downturn and stock market turmoil could deal yet another blow to retirement savings at a time when employees are already being squeezed by higher health-care costs or worse - layoffs. Twenty one percent of the 248 employers recently surveyed by Watson Wyatt Worldwide said they had already raised employee contributions for health care, and 25 percent said they planned to do so in the next 12 months. Nineteen percent said they had laid off workers, and 26 percent said they planned to cut jobs in the next 12 months.

For now, suspending or reducing 401(k) contributions remains a last resort for troubled businesses. The Watson Wyatt survey found that only 2 percent of employers had done so and that 4 percent said they planned to in the next 12 months. More companies may consider it if their financial position gets worse.

Companies cut back on 401(k) contributions during downturns in the 1980s, 1990s and during the economic slump that followed the terrorist attacks on Sept. 11, 2001. In many cases, they restored the matching payments within three years.

So what do you do if your employer decides to cut back on matching payments to your 401(k)?

First, get a handle on how much the change would set back your retirement goals. "Redo your financial planning and figure out if you need to save more now," said Robyn Credico, Watson Wyatt's national director of defined-benefit consulting.

The best option for the vast majority of workers, several financial planners said, is to keep putting in money because the market will rebound eventually.