CHICAGO (AP) _ Doctors on Saturday awaited a third liver they could transplant into a 6- month-old girl whose body rejected the first organ last month and who received the failing second organ late last week.

''It just is not doing the job for her,'' said Anne Duggan, a spokeswoman for the University of Chicago's Wyler Children's Hospital, where Meghann LaRocco remained in critical condition after the latest transplant.

Meghann's case attracted national attention after thieves took 22 of the donation cans her parents, Shirley and Frank LaRocco, had put in stores to collect money for the original transplant.

Surgeons implanted a liver Nov. 29 and another one in an overnight operation that began Thursday. Ms. Duggan said the second liver turned out not to be fully functioning.

''She is on top priority for getting an organ, but it is all luck,'' Ms. Duggan said. ''It has to be the right size for a child and to match tissue and blood type.''