Marriott Corp. said yesterday it has laid off 125 employees and will likely make further cutbacks as it responds to a slowdown in the hotel and real estate industries.

Most of the layoffs affect workers in the Washington area, especially at Marriott's headquarters in Bethesda, according to company spokesman Robert T. Souers. The most recent round of cuts occurred over the past two weeks in Marriott's architecture and construction division, which has lost about one-third of its 900-plus employees since June.

Marriott said more reductions in that division are likely to result as various hotel projects are completed, but the company did not provide details.

While relatively small, the layoffs are the largest ever for the once highflying company and come as the most recent evidence of Marriott's efforts to pare back construction of new hotels. The company said three weeks ago that it would slash its capital spending next year and was placing on hold all new hotel construction for the 12 to 18 months. Marriott typically builds hotels and sells them to groups of outside investors while continuing to manage the properties for a fee.

In April, Marriott sold its Roy Rogers fast-food franchise and has been negotiating the sale of its restaurant division. It has virtually eliminated the development of new restaurants.

Marriott's stock has been beaten down over the past nine months by fears of a recession, which would deepen problems in the already glutted hotel business, and by the slumping real-estate market, which is making it harder for Marriott to sell its hotels. Marriott's stock closed at $9.12 1/2 yesterday, up 25 cents.

Marriott was the second-largest private employer in the Washington area at the end of 1989, with just over 24,000 workers, behind Giant Food Inc. with 26,700.