D.C. Mayor Marion Barry asked the federal government yesterday to give the city a vacant lot near the D.C. Superior Court complex downtown to be used as the site for a 250-bed minimum-security prison.

D.C. Corrections Director Hallem H. Williams Jr. disclosed the city's plan to build a prison during a hearing on continued crowding at the city's Maximum and Central facilities at Lorton.

Barry's request for the tract was contained in a letter, dated Dec. 15, that Attorney General Edwin Meese III received yesterday. The parcel is believed to be at Fourth and D streets NW and has not been mentioned previously as a site for a correctional facility.

Barry and City Administrator Thomas M. Downs would not comment on the plans last night.

Williams said the new facility would be designed to house inmates in a structured setting before their release to a halfway house.

Williams said the facility also would be used as a headquarters for a new electronic surveillance program that would be able to serve about 120 people a year. Electronic surveillance programs allow officials to monitor the movements of prisoners who are usually permitted to live at their homes but whose travel is severely restricted.

Williams said in a brief interview that he could not say how much the new prison would cost or when it might become operational. The facility would be in addition to the new 500-bed prison and treatment center under construction on a site adjacent to the D.C. Jail, in D.C. Council member Nadine P. Winter's Ward 6.

Winter had complained bitterly that additional prison space should be built in the downtown business areas rather than in residential neighborhoods.

Construction on the 500-bed prison, which is being built with $50 million in federal funds, was halted in September by the Senate Appropriations subcommittee on the District after area residents complained that the construction was destroying historic Civil War and Indian artifacts.

The General Accounting Office and the Bureau of Prisons have been examining several alternative sites, and the GAO is to submit a report on Feb. 1.

The hearing yesterday was on a request by Peter J. Nickles, an attorney for Central and Maximum inmates, to increase the daily fines imposed for exceeding the inmate population limit at Central.

Although the number of inmates housed at Central has exceeded the court-ordered limit all but one day since June, Williams said that the Central count was in compliance as of 4 a.m. yesterday.

Two days earlier, Central housed 107 persons more than the court limit. Williams said the "domino effect" caused by the release of 109 prisoners under the Emergency Prison Overcrowding Act made it possible to meet the court-imposed limit yesterday.

U.S. District Judge June L. Green ruled that the city had remained in contempt of court for violating the inmate population limits at Central and said the city is now liable for nearly $400,000 in fines. But Green said she would not increase the daily fines of $250 per dormitory.

Green did not order the city to pay the fines immediately, because the city has appealed to the U.S. Court of Appeals to overturn her finding of contempt.

During the hearing, Williams also disclosed that:A 100-bed modular facility that the District purchased from Prince George's County for $1 should be ready for occupancy about the middle of January. The building is being erected on the grounds of Lorton's Central facility. The city will have spent about $500,000 to move the 10 modules and put them in place.

The city plans to add at least 214 additional halfway house beds at three locations before Sept. 30. The first 50 beds should be available in 60 days, Williams said. He would not disclose the locations of the new halfway houses.