The General Services Administration will begin selecting designers to complete the Federal Triangle in downtown Washington later this year if the proposed 1983 GSA budget passes the Congress intact.

Although GSA long-term plans call for several other new federal buildings in the Washington area, the 1983 budget does not propose funding for them.

The administration has included $3.5 million in the Public Buildings Service budget to plan two Federal Triangle facilities that would house 9,000 employes, possibly from nearby agencies such as the Department of Justice or from a number of federal commissions currently scattered about the Washington area. The buildings are planned for what is now a large parking lot behind the District Building at 14th Street and Pennsylvania Avenue NW.

The decision to continue with new government construction in the face of a shrinking federal work force is in keeping with GSA's stated intention of moving employes from leased space into government-owned space, according to a GSA spokesman.

Currently, about half of the federal office space in the Washington metropolitan area is leased. GSA planners say they hope to reduce that amount to about 20 percent.

The budget does call for $24 million to carry out long-standing plans to renovate the old Pension Building on G Street between 4th and 5th streets NW. The Pension building currently houses the private National Building Museum and several Park Service offices.

If all goes according to GSA's schedule, the Federal Triangle construction will begin in 1985 and will be completed by 1990. A preliminary master plan prepared by Harry Weese & Associates architects calls for two 10-story office buildings with between 1.3 million and 1.6 million square feet of new office and commercial space as well as underground parking for about 2,100 cars.

Although they have not yet decided who would occupy the building, GSA planners say they'd like to gather together a number of federal commissions that are scattered around the the Washington area.

The next step in the Federal Triangle planning process will be to present the master plan to the Capital Planning Commission for approval, according to Public Building Service planning director Jack Finberg.