Doctors who transplanted part of a woman's lung into her dying daughter said the procedure - believed to be a first in this country - greatly reduces the chances of transplant rejection.

The girl, 12, and her mother, 46, whose names were withheld at the family's request, were reported in good condition after their operations Thursday at Stanford University Medical Center."The mother was a far closer tissue match than could have been expected from an unrelated donor," said Dr. Vaughn Starnes, who heads the medical center's heart-lung transplant team.

Kidneys and a portion of a liver have been transplanted from living donors, but all lung transplants in this country have previously involved brain-dead donors, Stanford officials said. People have survived removal of a diseased lung.

Starnes said that the mother and child matched on four of six genetic markers, or tissue antigens, compared with no more than two such matches in previous lung and heart transplants involving brain-dead donors.