Employment has increased more slowly in commercial neighborhoods near Metro rail stations than in other parts of the Washington area, according to a study by the Metropolitan Washington Council of Governments.

"You do not find astronomical growth of employment around stations," said Joe Cater, a COG official who prepared the report. "It's been a rather modest picture."

One of the goals of building the subway system has been to spur economic development along transit corridors, the report noted. Cater said the findings should lead to more "realistic expectations" about the rail system's impact on employment.

The report, which was completed last month as part of a series of COG studies of the rail system's impact on the region's economy and transportation network, examined employment trends from 1976, when subway service started, to 1980, the latest year for which overall employment data is available.

Employment in areas near rail stations rose by 6.1 percent between 1976 and 1980 -- a markedly slower pace than the 8.9 percent increase in jobs for the region as a whole, the study found.

In suburban areas where most of the job gains occurred, employment increased by 11.7 percent near Metro stations, falling short of the 15.9 percent growth rate for jobs at other employment sites not considered within walking distance of Metro stations.

In the rapidly expanding services sector, which includes jobs in computer, data processing, engineering, architectural, health, legal and other business services, the study found:

"The proportion of services employment in Metro station areas decreased from 59 percent of all services jobs in 1972 to 56 percent in 1976 and to 51 percent in 1980. This trend suggests an increase in the number of new services jobs located outside of Metro station areas."

Some officials said the study underscored widespread concern that the multibillion-dollar rail system may not serve some fast-growing suburban employment centers. Officials long have warned that despite the Metro system's construction, more highways will be needed to accommodate suburban residents who commute to suburban jobs.

The findings appeared to confirm a pattern that emerged in an earlier COG study compiled from data before the rail system opened. Between 1972 and 1976, employment rose by 4.7 percent near planned Metro stations -- a slower rate than the 8.1 percent increase for the region, the earlier study showed.

The new report said that employment trends in areas where stations are planned, but not open, are significant because of an "anticipatory effect" evident near stations. Job growth often is faster near a station before it opens than afterward, the study found.

The report analyzed jobs within 0.7 mile, or about a 15-minute walk, of sites where Metro stations were open or planned. In outlying sections of the District and suburban areas, the study said, employment increased 12 percent near unopened stations but decreased 0.1 percent near open stations.

Robert A. Pickett, assistant planning director for Metro, said the study's findings should not be viewed as "necessarily bad" because there may be a "big lag" before job increases occur near some rail stations. In addition, he said, it may be desirable for suburban stations to be situated near residential as well as commercial areas.

"These projects take a long time to get under way," Pickett said, citing development plans near the Gallery Place, Clarendon and Silver Spring stations. "You had to have the fact of having rail there before these projects got off the ground."

Robert T. Dunphy, a former COG official who oversaw the Metro studies and is now a senior associate for Planning Research Corp., said it was "not unreasonable" to expect slower employment growth near Metro stations because stations frequently were planned in "established corridors." There is less room for job expansion at these sites than in undeveloped areas, he said.

Cater, Dunphy and other officials pointed to several reasons for faster employment growth in suburban areas away from Metro stations. Some employers, they said, may be more concerned about access to highways than mass transit.

"Being close to Metro stations isn't as much of a plus as transportation people would like to believe," said Thomas Muller, an Urban Institute economist.

Some expanding businesses, such as computer and electronics equipment manufacturers, may rely heavily on trucking, officials said. In addition, suburban employers normally assume that most employes will drive to work from outlying or nearby suburban neighborhoods rather than commute from the District or inner suburbs by rail.

Some businesses seek lower rents or land prices and more space than may be available near Metro stations, where development often drives rents up, the study said. For some firms, Cater said, another key aim is choosing a site near other businesses in allied fields.

Some officials said employment growth also may be limited by curbs on development imposed as a result of complaints from community residents.