NEW YORK (AP) _ Three days after Malcolm X's widow nearly died in a fire, surgeons began replacing her charred tissue with artificial skin Wednesday in a procedure that is her only hope of survival.

Betty Shabazz, 61, suffered third-degree burns over 80 percent of her body in the fire early Sunday at her Yonkers apartment. She was in critical condition at Jacobi Medical Center.

Her 12-year-old grandson is suspected of setting the fire. He has been held for medical and psychological testing pending a hearing Friday in family court.

On Wednesday, surgeons removed 20 percent of Mrs. Shabazz's damaged skin and stapled a translucent velvety material called Integra, which stimulates tissue regeneration, onto the remaining flesh.

Dr. Bruce Greenstein, head of the burn unit, said he was pleased with the way Mrs. Shabazz tolerated the four-hour surgery. He said doctors would try to remove another 20 to 25 percent of burned skin on Thursday, if her condition remains stable.

``It really will take weeks before her condition is upgraded,'' he said. ``She remains in the same critical but stable condition.''

Because burned skin is prone to infection and causes massive loss of fluids, it must be replaced if the patient is to live. Statistically, patients with Mrs. Shabazz's injuries have less than a 10 percent chance of surviving.

The hospital harvested the top layer of skin from undamaged areas of Mrs. Shabazz's body so that it can be applied over the Integra in a few weeks.

Malcolm Shabazz, who had been living with his grandmother for about three weeks, told police he tried to kill Mrs. Shabazz in the hope he would be reunited with his mother in Texas, the Daily News reported today. Police and prosecutors declined to comment.

Larry Dais, a Columbia University publicist and family friend who spoke to Malcolm soon after police questioned him, said he was sure the boy ``under no circumstances would try to hurt his grandmother.''

Dais said he thought the boy ``was attempting to create a situation that may have convinced the grandmother that this is the last straw, `I'm going to send you back to Texas.' Clearly, he wanted to go back to Texas.''