The legal profession, which a decade ago welcomed the growing cadre of female lawyers, now is struggling to retain them as many women opt for other careers once they confront family issues and encounter sexual discrimination.

Increasingly, women lawyers are finding that it is difficult, and sometimes impossible, to compete for partnerships in major firms and maintain a fulfilling family life. They also are discovering that despite their increasing numbers, women lawyers still encounter both subtle and overt discrimination in what remains a male-dominated profession. As a result, many are choosing less demanding careers as government attorneys, or abandoning the profession altogether."Women are the most apt to be dissatisfied because they are trying to juggle a normal family life with a demanding profession," said Barbara Mendel Mayden, an associate at the law firm of White and Case in New York. "Being a full-time mom and billing 2,200 hours per year is an impossible situation . . . Those who make it are finding that they give up a lot personally."

Mayden cites two findings as examples of the difficulties women encounter. First, women who become partners are less likely to be married or have children, and, second, they are more likely to be divorced, according to recent bar studies.

The legal profession has been at the forefront when it comes to women trying to succeed in largely male-controlled occupations. Today, women comprise about 20 percent of attorneys in the legal profession, compared with 3 percent in 1970.

The law has attracted some of the smartest and most ambitious women in the country. But now that the profession is faced with defections, some are questioning whether their difficulties reflect certain limitations of the whole women's movement. Others dispute that assessment, saying instead it is an issue the entire profession must address.

"This is not a women's issue; it is a societal issue," said Gene D. Dahmen, a partner at the Boston firm of Homans, Hamilton, Dahmen and Marshall and past president of the Boston Bar Association.

The exodus of women, particularly from major metropolitan law firms, is alarming to many legal experts because it means that the profession is losing some of its best and brightest young attorneys. Although the profession is trying to counter the problem, it has so far been largely unsuccessful.

Alice Richmond, a partner at Hemenway and Barnes in Boston and past president of the Massachusetts Bar Association, said, "I despair about substantive change. I don't think the real centers of power are ready to have women in them. What I see are capable young women just dropping out."

For those who stay in private practice and try to juggle family and career, the competing demands are wearying. As a result, a two-tiered system sometimes referred to as the "mommy track" is emerging in some major law firms. Its women bill fewer hours and thus are able to spend more time with their children, but they give up the opportunity to become equity partners. Some see it as a means of stratifying the sexes rather than unifying them.

"There must be some solution that does not make women into second-class lawyers," Dahmen said. "I think there is a calibrating going on now . . . there is a need for professional life to accommodate family life."

A woman lawyer who asked not to be named said the "mommy track" may help law firms' bottom line, but "a firm will be confronted with the fact that it has 15 bright women who won't be partners simply because they are mothers. That will be hard to defend."

Margaret Marshall, a partner at the Boston firm of Csaplar and Bok, said she encourages young women to "pace themselves and not be so anxious about achieving everything at one time."

Marshall acknowledges that her career has been more successful because she doesn't have children.

Interviews with more than 25 lawyers working in virtually every segment of the profession found that women are encountering significant discrimination that is prompting many to rethink their career goals.