More than two years after the General Services Administration decided to abandon eight floors of an office building in Hyattsville, the space remains under lease to the government -- and empty.

The long-running case illustrates some of the problems that have beset the Reagan administration's efforts to reduce the office space agencies use. And it shows how decisions intended to save money can sometimes run afoul of the wishes of Cabinet secretaries.

The saga began when the Agriculture Department cut its staff and decided to vacate its offices in what is known as the Center Building No. 2 at 3700 East-West Highway, when the lease expired in January 1984. The GSA decided to give up the space because no new tenants were in sight.

But after then-GSA Inspector General Joseph Sickon pointed out that the agency could rent the space for a very low rate if it exercised an option to extend the lease for five years, then-GSA Administrator Gerald Carmen told subordinates to extend the lease and find a tenant.

GSA first tried to get Agriculture's Economic Research Service to move from 12th and C Streets SW, because the government was being forced to vacate its offices there. Agriculture Secretary John R. Block appealed the decision to the White House. Eventually, aides there said the research service could stay, but that another USDA division would have to go.

Instead, GSA sought another target: the Treasury Department's Financial Management Service, which was scattered in offices around downtown Washington. Not only did it want to consolidate its offices, but its largest unit was in the World War I-vintage Liberty Loan Building, which GSA wanted to vacate so it could be renovated.

But Treasury refused to move, sending in Secretary Donald T. Regan and Terence C. Golden, then assistant secretary for administration, to ask that the offices be consolidated in downtown Washington or left alone. Since then, Golden has been nominated to be GSA administrator.

"It is just the nature of bureaucracies and hierarchies that people take things up the chain of command to the highest level," said William F. Sullivan, the GSA's current Public Buildings Commissioner.

To try to resolve the stalemate, last October GSA officials got the House Appropriations subcommittee that handles funding for GSA and Treasury to include an amendment to the appropriations bill ordering Treasury to move. But it did not set a date.

In early January, the GSA declared that Treasury would have to vacate the Liberty Loan Building by March 31. Golden negotiated a six-month delay. He has declined to comment.

GSA Regional Administrator William F. Madison said the additional delay will cost the government more than $500,000 in rent and, because the move is considered a "forced relocation," the GSA will have to pay up to $4 million to renovate the Hyattsville building to accommodate Treasury's computer equipment.

Madison said that the cost of leaving the building vacant is about $79,000 a month for a total, so far, of $1.746 million. By October, he said, the tab will hit $2.143 million.

"While, in my opinion, this administration has made great strides to avoid politicizing the good management of government, this is one case where they're falling down," said Richard Haase, who headed the GSA's Public Buildings Service when the issue first heated up in 1983. "What GSA needs is for the White House to put its foot down when there's political interference and say 'no more.' "

Last week Treasury officials let the GSA know that their equipment would not be ready to move in until December. One top GSA official said: "It is getting to be a comedy."