The City of Alexandria asked a federal judge yesterday to settle a 4 1/2-year feud with the General Services Administration over the sale of a choice acre of surplus U.S. property in the city's booming Old Town section.

City lawyers charged GSA improperly reneged on an agreed-upon price of $925,000 for the parcel, now a parking lot at 219 N. Lee St. near the city's rapidly developing Potomac riverfront.

Although the City Council approved the purchase in 1979 after several years of debate, according to a complaint filed yesterday in U.S. District Court, GSA delayed the sale for more than two years. It then maintained the property had risen in value to $1.5 million and returned the city's $92,500 deposit without interest.

In May the council approved the deal at the higher price, but said it reserved its right to pursue its original deal. GSA rejected that and advertised the property for public sale Aug. 31.

Councilman Donald E. Casey said yesterday the city's latest legal maneuver, which asks the court to force GSA to stick to its original price, is designed to block the sale.

"It's politics," said Casey, a member of the council's Democratic majority. Casey said GSA, which under the Reagan administration has embarked on a program of raising revenue by selling off surplus government lands, is now seeking higher appraisals where earlier agreements have not been concluded.

"I get a little disgusted," said Casey. "They went up more than a half-million on their price. We thought for half a million dollars, we'd litigate."

Casey said the council will warn potential private purchasers that the city will condemn any future building on the site.

Alexandria officials want the site to remain a parking lot in the short-term to ease traffic problems in the Old Town area, both Casey and Alexandria City Manager Douglas Harman said yesterday. The city's long-range plans call for further development of the property while retaining parking facilities on the ground level, they said.

The site is adjacent to the aging Torpedo Factory complex, where recent renovation work to make way for new commercial and residential development has worsened traffic.