Edward Ford, currently serving a life sentence for murder, was convicted yesterday of first-degree murder for the execution-style slaying of a Northwest Washington man.

Prince George's County Circuit Court Judge Howard S. Chasanow sentenced Ford, 32, to life in prison for the murder of Gary Edward Green of 404 U Street NW. The sentence will run consecutive to life sentence he received last year after he was convicted of slipping into the Lorton correctional facility and killing an inmate.

Both murders were drug-related. The Lorton inmate was killed in revenge for the breakup of Ford's Washington drug ring, while Green was killed for telling police that he had purchased the drug dilaudid from Ford, according to testimony in the cases.

Green's body was discovered March 8, 1980 in a wooded area of Upper Marlboro, along the 4700 block of Nelwood Road. He had been shot in the head six times.

According to court testimony, Ford killed Green the night of Feb. 26, 1980, one day after Green told D.C. police that Ford sold him a bottle of dilaudid. Dilaudid is a depressant frequently used in place of heroin.

Several of Ford's former friends and acquaintances testified for the prosecution, claiming that Ford had told them he killed Green. In addition, one friend, Ronnie Harris, testified that he was with Ford when he tossed a .38 caliber revolver -- the alleged murder weapon -- into the Anacostia River several days after the murder.

Ford testified, however, that Green was one of his best friends and that he had no reason to kill him.