ATLANTA (AP) _ A gunman critically wounded his wife and her companion in a busy hospital clinic before fatally shooting himself, police said.

James Howard Jr., 49, died of the self-inflicted wound Wednesday night in Grady Memorial Hospital's surgical emergency clinic, police Sgt. Dean Gundlach said.

Howard's 36-year-old wife, Marguerite Howard of College Park, and her 29- year-old companion, Henry Ector of Atlanta, were in critical condition today, said hospital spokeswoman Beverly Thomas.

Two other people suffered minor wounds.

The clinic is a long room adjacent to smaller operating rooms and waiting areas. Police said the man, wearing the uniform of a private security company, came to the clinic about 6:30 p.m. and began arguing with his wife and her companion, who was awaiting treatment of a leg problem.

Witnesses said the man pulled a revolver and opened fire about 7 p.m.

Mrs. Howard was shot three times, twice in the head and once in the arm and neck, Gundlach said. Ector was struck in the forehead.

Bonnie Collett of Alpharetta and her 9-year-old great-niece, Julie Garner of Dawsonville, who were among a group of relatives accompanying an accident victim, were slightly wounded by flying fragments, said Renee Yates, Mrs. Collett's daughter.

''She was so upset,'' Mrs. Yates said. ''He (the gunman) was sitting right next to my aunt. Mother said she got down under something and hid and (a bullet) grazed one of her arms and then grazed one of (the child's) ears.''

''All I can do is thank God I'm alive,'' said Avon Francis of Decatur, who was waiting for a prescription when she heard noises she did not immediately recognize as gunshots.