U.S. News & World Report, looking to trim costs in tough economic times, has offered a special early retirement buyout to some of the magazine's employees, officials confirmed yesterday.

"It's an opportunity to cushion ourselves in case the economy worsens," said Kathryn A. Bushkin, a spokeswoman for the magazine.

Bushkin said that while the magazine, like many others, already has a freeze on hiring, it has no plans to take other steps to reduce the number of employees.

Thirty-seven of about 400 employees are eligible for the buyout, company officials said. Employees must be at least 50 and have five or more years of employment at the magazine to qualify for the plan. It offers them one year's salary and 18 months of health, dental and life insurance benefits, in addition to accrued retirement benefits.

Washington-based U.S. News, owned along with the Atlantic magazine by real estate developer Mortimer B. Zuckerman, is the nation's third-largest weekly news magazine, trailing Time and Newsweek in the number of subscribers. All three are suffering from a softening national advertising environment.

Advertising is frequently one of the first items to be cut by companies in lean years, and many magazines and newspapers are struggling with greatly reduced ad revenue. Magazines also have suffered recently from large cost increases, mostly involving higher postal rates.

Ad revenue at U.S. News was flat or up slightly in 1990, according to its president, Fred Drasner. The magazine had to raise advertising rates to accomplish that, since the number of pages of ads was down.

"Financially, we think we had a very successful year, considering the environment," Drasner said.

U.S. News has consolidated its printing in one plant to reduce costs, he added.

Several employees who received the offer said yesterday that those near 60 seemed inclined to take the buyout, while those nearer 50 were more likely to stay.

New jobs may be difficult to find in an environment where many publications have died or cut back their work forces, they said.