Many employers are expected to limit workers' pay raises and benefit increases next year to what could be the smallest percentage gains since 1987, and perhaps the 1970s, as a result of economic hard times and low inflation.

"Employers are going to be very stringent," said Audrey Freedman, a labor economist for the Conference Board, an influential business research group in New York. "There's no other choice right now."

At the same time, companies are relying more on merit pay and less on cost-of-living increases, a trend that could spread raises among fewer employees.

Next year will bring continued "stagnation or slippage" in the standard of living of the average worker, said Sar Levitan, director of the Center for Social Policy Studies at George Washington University in Washington.

Analysts generally say the lower pay and benefit raises will restrain the nation's recovery from recession over the coming year by dampening consumer spending. Still, economists said, slower increases in employers' payroll expenses could pave the way for a moderate but long-lasting economic rebound later in the decade.

In one of the more dramatic moves, Hughes Aircraft announced this week that it would try to hold down expenses by freezing its executives' salaries next year and by delaying the salary reviews of 55,000 employees from March to July. Slumping USAir asked its unions to accept 15-month pay cuts for 47,000 U.S. employees to try to save the company $400 million in 1992.

More typically, though, employers are expected to make small to moderate cuts in pay and benefit increases in 1992. Meanwhile, USAir and many others also are asking employees to foot more of the cost of their health insurance.

Last year, the U.S. Bureau of Labor Statistics' employment cost index--considered the best barometer of American wage and benefit increases--climbed 4.9%. The most recent statistics available showed the same rate of increase in the first half of this year.

But next year, Freedman estimated, the figure for all civilian workers will be about 3.5%--the lowest level since the federal government began publishing the index nearly a decade ago. Even if the 1992 increase is as high as 4%, as projected by many other economists, it would be the smallest gain since the 3.6% rise in 1987.

"It's not going to be a good year," said UCLA labor economist Daniel J. B. Mitchell, whose own preliminary estimate is for the index to rise about 4%.