The Washington Post Co. is negotiating to buy a 33-acre tract of land near the Capital Beltway in Prince George's County that may serve as the site of a new printing plant.

Washington Post Senior Vice President Theodore C. Lutz said the newspaper was conducting feasibility studies on the site, which would cost about $10 million.

The land is in an industrially zoned area at the intersection of Pennsylvania Avenue and the Beltway. The seller is a joint venture headed by construction executive John Driggs.

Lutz said that if the Post decides to buy the site, a decision to build a production facility there would still be a few years away.

He said the decision to look for land now was prompted by concerns that relatively large tracts of property near the Beltway are becoming increasingly scarce.

"It's one of those tough decisions where you're trying to get ready for the future and seeing through a glass somewhat darkly, but trying to be prudent in dealing with a shrinking resource," he said.

The Post has printing plants at its downtown headquarters at 15th and M streets NW, in Southeast Washington at the old Washington Star plant, and in Springfield. The Springfield plant opened in 1980 and employs about 400 workers.

The Post also owns a 10-acre tract in Montgomery County near White Oak.

Lutz said the newspaper's subscribers are moving farther away from downtown, making the need for additional production facilities more acute.

The need to produce larger newspapers, as well as the increasingly sophisticated equipment needed to handle preprinted advertising material that is inserted in the newspaper, contributes to the need for additional facilities, Lutz said.

"We've got to get these papers out, and we can't expand time," he said.

The Post may still decide not to buy the site now under study without losing money that it has deposited, Lutz said.

Considerations under study include whether height limits -- necessary because of the proximity to Andrews Air Force Base -- and other environmental restrictions or factors might prevent the construction of the type of facility the Post may need.

The Post also announced Friday that it will show an after-tax gain of about $45 million on two transactions: the sale of its minority partnership interest in Detroit Cellular Telephone Co. to subsidiaries of Pacific Telesis Group and the sale of its minority interest in the Washington-Baltimore cellular system to Soutwestern Bell Cor