The Reagan administration plans to ask agencies to share a wide array of support services to cut costs and reduce the federal work force.

Under the proposal, agencies that share buildings would share such services as in-house mail delivery, procurement offices and some data processing. A pilot project in up to 14 federal buildings is expected to save perhaps $25 million this year and eliminate 950 to 1,900 employes, according to Dennis M. Boyd, deputy associate director of the Office of Management and Budget. The buildings serve three to 40 agencies.

Boyd said that if the program is expanded to all 900 buildings that house at least three agencies, 7,000 jobs could be eliminated and about $200 million saved each year.

The idea, Boyd said, is "to get agencies to share because it will save them, and the federal government, some money. We don't need eight procurement offices in the same federal building, or blue-collar workers from eight agencies delivering the mail."

Agencies will be asked to share mail pickup, sorting and delivery; printing, duplicating and copying; furniture moving; warehousing and temporary storage; data and text entry; library facilities, and small purchases of supplies. Agencies that want to share other services would be encouraged to do so, Boyd said.

Officials from the General Services Adminstration, which would supervise the program, have expressed some reservations. In a February letter, then-acting administrator Ray Kline said "this project can be a real cornerstone" of the administration's management revisions. He added that it also could help the OMB reshape the federal field structure.

But he warned the OMB that, "Without unwavering support from the highest levels of the administration, clearly expressed to department and agency heads, the effort will fail."

Vito T. Chiechi, the GSA's regional administrator in Seattle, wrote Kline that officials at the agencies involved might consider the program "threatening."

"Lacking a White House directive, some agencies can be expected to resist the entire common-services concept, preferring to retain full control of their current administrative service staff," Chiechi said. "There will be uncertainties about what the common services costs charged by GSA will be, quality of service and how the process will ultimately benefit their agencies."

The OMB, however, has balked at the idea of having President Reagan issue an executive order that would require agencies to consolidate operations. Instead, the OMB wants to monitor agencies' cooperation through the semiannual management reviews conducted by Deputy OMB Director Joseph R. Wright and his staff.

Meanwhile, GSA officials are looking for buildings where the approach could be tested. One possibility is Atlanta, where officials from the Health and Human Services Department have expressed interest in directing services for agencies in the Gateway Federal Building. The HHS has 1,126 employes in the building; the Labor Department has 554; the Education Department, 173, and the Interstate Commerce Commission, 39.

"The rule of thumb that we're operating with says that for every 300 employes, about 10 percent are involved in administrative support services," said Clarence Lee, deputy associate administrator of GSA for policy and management systems. "Out of those 30 people, six to 12 people could be eliminated."

The idea of consolidating services is not new, but it has not gained wide acceptance among agency officials who have been concerned about losing part of their turf.

"We're not going to be putting people out in the street," Boyd said, explaining that there is a high turnover rate in the kinds of jobs that are involved. Still, he acknowledged that some workers might be laid off if jobs go to private contractors.