John M. Mudd, a Washington liquor store owner who was charged with being part of a major cocaine and PCP distribution ring, pleaded guilty here last week to possession of cocaine that was seized in May in his Southwest Washington apartment.

In the same court proceeding Friday, Mudd, 53, pleaded guilty to possessing a stolen pistol that police found in the apartment at 429 N St. SW.

He faces a maximum sentence of 13 years in prison and a $35,000 fine on the charges.

Mudd was convicted in U.S. District Court here in April of receiving a stolen government computer and possessing three unregistered handguns.

At sentencing on those charges, he was placed on probation and fined $11,000 by Judge Thomas P. Jackson, who said Mudd had "led an exemplary life" until last year.

Mudd owns Fair Liquors at 5008 First St. NW and for years was one of the top-ranked black tennis players in the country. During the five-day trial on the computer charge, he was warmly praised by a string of character witnesses, including David Wilmot, general counsel to the Washington Convention Center and a professor at Georgetown University Law School.

In court papers filed later, however, Assistant U.S. Attorney E. Thomas Roberts said Mudd told an undercover police officer that he sold about 16 kilograms of cocaine during May. Roberts added that besides cocaine and the stolen pistol, agents of the FBI and the U.S. Drug Enforcement Administration seized "a large sum of money and narcotic distribution paraphernalia" in Mudd's apartment on May 31.

Police have photographs showing Mudd using cocaine in Brazil with two men "known . . . to be high-level drug dealers," Roberts said.

Last month, Mudd pleaded guilty in federal court in Baltimore to conspiracy to distribute cocaine and use of a telephone to facilitate a narcotics conspiracy. Prosecutors dropped the conspiracy charges relating to PCP.

Jackson has set sentencing for Jan. 23, shortly after Mudd is scheduled to be sentenced in Baltimore. Mudd faces a maximum sentence of nine years in prison and a fine of $280,000 in the Baltimore case.