MANHASSET, N.Y. (AP) _ A comatose woman who received an abortion after a two-week legal battle was in guarded condition Sunday as her family explored moving her to a rehabilitation facility in New Jersey or Boston.

Nancy Klein, 32, was at North Shore University Hospital Sunday, with all signs stable, a hospital spokesman said one day after Mrs. Klein was given an abortion requested by her husband. She was 18 weeks pregnant.

Attorneys involved in the case said the court's decision to allow Martin Klein of Upper Brookville in Long Island to order an abortion for his wife broke legal ground.

''It was a tough case because we didn't have a law to directly point to for an answer,'' said Anthony D'Auria, an attorney for North Shore University Hospital.

Mrs. Klein has been in a coma since she was severely brain damaged in a car accident Dec. 13. Martin Klein, her husband of nine years, began court proceedings on Jan. 26 to become her guardian so he could order an abortion doctors said could aid her recovery.

Abortion opponents challenged Klein from local courts to the U.S. Supreme Court, losing when Justice Thurgood Marshall refused to issue a stay Friday. After overnight preparations, the abortion was performed Saturday morning - as activists still tried to find a legal way to stop it.

Mrs. Klein will remain in the hospital while her husband and other family members research a rehabilitation facility where she can be placed. Under consideration are places in New Jersey near where Klein's sister lives and one in the Boston area, family members said.

''I couldn't bear to be that far away from Nancy,'' Klein said last week.

One of the reasons Klein sought the abortion, he said, is that some rehabilitation facilities would not accept a pregnant woman.

After the abortion was announced, anti-abortion activist John Short vowed to press the appeal with the full Supreme Court, even though it is moot, to set a precedent so similar cases would not occur.

But the ruling may have dealt a blow to opponents who have attempted to intervene in cases where they apparently have no clear-cut interest legally, some lawyers said.

''One of the important aspects of this case is that it is the first time a court has squarely said to these pro-life groups: It is inappropriate to interfere in the private decisions of a family,'' said Elizabeth Bradford, an assistant state attorney general whose office was called in to take part in the proceedings.

A New York state appeals court, in dismissing an appeal from Short and John Broderick, another activist, called them ''absolute strangers'' who, ''whatever their motivation, have no place in the midst of a family tragedy.''

''The importance of this case is that it establishes that the next of kin need only prove that the patient is incapable of forming an opinion or granting consent,'' said D'Auria. ''Under this ruling, it would be no longer necessary in the state for courts to weigh the relative risks or advantages, or even necessity, of an abortion.''

In issuing the first ruling in the case, Nassau County state Supreme Court Justice Bernard McCaffrey rejected the contention that this was a decision where there had to be clear and convincing evidence of what the woman's wishes would have been, before an abortion could be performed. In New York state, the Supreme Court is a trial-level court.

D'Auria said that father's rights also may have been furthered by the case.

''This case has marked a slight departure from previous existing law that stated that fathers do not have the right to determine whether a woman should have an abortion,'' D'Auria said.