The Beltsville Agricultural Research Center probably won't be sold "in this administration," a top General Services Administration official said this week after the agency received a letter from Sen. Ted Stevens (R-Alaska)--chairman of a GSA Senate oversight committee--recommending that the sale be put on hold.

GSA officials had drafted an internal memorandum indicating that the Federal Property Resources Service firmly opposed Senate legislation sponsored by Sen. Charles Mathias (R-Md.) that seeks to keep BARC in federal hands.

But conflicting signals from Stevens' subcommittee staff last week threatened to prompt GSA to go the other way, and recommend going ahead with the sale unless hearings actually were scheduled.

Wayne A. Schley, staff director of Stevens' Senate subcommittee on General Services, said there "may be hearings; we don't know yet, for sure. We wrote to GSA because Mathias is a Republican and he is on the Governmental Affairs Committee."

Although Mathias' action may have obtained the desired result, it left Sen. Paul S. Sarbanes (D-Md.) hanging. Sarbanes cosponsored the Mathias bill and issued a press release claiming victory and cheering the hearings.

"In my view, the decision to dispose of property at Beltsville was hasty an ill-considered," Sarbanes's statement proclaimed. "It grew out of the Reagan administration's attempt to generate short-term revenue by disposing of important capitol assets. This policy is not working and needs to be carefully reassessed."

"What do you mean, there may not be hearings?" retorted a confused Sarbanes staffer last Monday.

A GSA spokesman said the letter was being "rewritten" and would not comment on which way it leaned.

Earl E. Jones, GSA's assistant commissioner of real property, said it is standard procedure to back off from a sale if congressional hearings are scheduled.

"We have a mission, and that is to sell the property that has been determined excess to the needs of the agency that held it," in this case, the Agriculture Department, Jones said, explaining that, in that context, GSA is but a middleman--"open-minded and willing to listen to the guidance from Congress."

After learning that Discount Brokers Inc., a commercial automobile loan firm, was illegally occupying space in a federal building here, General Services Administration realty specialists drew up a lease and asked the company to sign on the dotted line. Now Discount Brokers will have to pay $985.44 a year to rent 135 square feet of space in old Navy Yard Building 159.

Discount Brokers got into the space in connection with services it performs for the nonprofit Federal League of Recreation Associations. The association has been reprimanded for improperly allocating federal office space.

GSA regional realty chief William B. Jenkins said he does not think there is a plethora of illegal occupants of federal space. "Nonprofit groups can do this, but not companies that operate for a profit," Jenkins said.

After reviewing the U.S. Information Agency's space requests for its new headquarters at 400 C St. SW, GSA surrendered the unneeded portion of the building. But when USIA counted a second time, it found that the 11,000 square feet of ground floor space would just fit the people it "missed" in the first count.

By this time, the builder, Donohoe Construction Co., was trying to lease the space to retail shops and had set the rate at $29 a square foot, above the $25 a square foot GSA originally would have had to pay.

To complicate matters, GSA wanted the space at $16 a square foot--the average rate for space in the building. As could be expected, Donohoe refused. As a result, GSA will locate the additional USIA employes across the street in the 43-year-old Mary B. Switzer building.

The General Services Administration has sold $16.58 million worth of unneeded federal property on the open market in the last four months, bringing its fiscal year take up to $18.5 million.

The new sales included 1,188 acres of federal land. In October and November, GSA sold 634 acres.

Here's a capsule look at the sales over the past four months and the properties on the block in April.