In a sign that its once-ambitious hotel-building plans are flagging, Marriott Corp. has laid off 20 percent of the people responsible for designing new hotels.

The layoff of about 40 workers in Marriott's architecture design group late last week comes only a few months after the Bethesda-based corporation decided to sell off several divisions, including its Roy Rogers fast-food chain, in order to concentrate on hotel development and contract-services such as hospital food-service management.

But lodging-industry analysts have warned repeatedly that the nation's hotel market is glutted after years of heated development activity. Fears that the market is overbuilt have depressed the stock-market prices of several hotel-industry stocks, including Marriott's, during the past six months.

Marriott, which operates 550 hotels worldwide, still plans to have nearly twice that number of properties under management by the mid-1990s, said a company spokesman, Robert T. Souers, yesterday. But Souers said the company would accelerate its purchases of existing hotels rather than build as many new ones.

"We are clearly in the short term not going to be building as many 'ground-up' hotels as we've said," Souers said. "We feel we'd like to see demand {for hotel rooms} catch up with supply."

The layoffs in the architecture design group affected professional and management employees, including design managers, project coordinators, draftsmen and civil and mechanical engineers.

The cutback is part of a "downsizing" strategy recommended last fall by the consulting firm McKinsey & Co., which undertook a yearlong study of the company's staffing requirements, said Clifford J. Ehrlich, Marriott's chief personnel officer, in a recent interview. The McKinsey study suggested cutbacks of about 100 people at Marriott's Bethesda headquarters, which Ehrlich characterized as relatively insignificant given that the company employs 4,500 people in its headquarters.

Souers said yesterday, "There could be additional layoffs, but they would be scattered" throughout several headquarters departments. "We hope to do it by attrition, but in any case, it would be a very small number."

In an unrelated move, Marriott confirmed that it is still seeking zoning approvals to build new office buildings on a 210-acre site it owns in Germantown. The company said in January that it was abandoning plans to develop the site and instead hoped to swap it for a smaller parcel off Interstate 270 in Rockville.

The company said yesterday it is still negotiating the land swap with the owners of the Rockville site, the Tower Companies, but "had no guarantees" that it would be able to complete a deal and wanted additional zoning approvals in Germantown as a backup. Marriott plans to build two office buildings totaling 500,000 square feet in Rockville.

It has government approval to build 467,000 square feet in Germantown but is seeking approval for a total of 707,000 square feet.