It is no secret among women that their friendships with each other can be supportive, loving and precious. What is secret -- and something few women like to admit to -- are the intense feelings of envy, competition and anger that sometimes threaten even the closest of friends.

Why are women's close friendships increasingly both bitter and sweet?

Psychotherapists Luise Eichenbaum and Susie Orbach believe it has to do with the changing nature of today's women. What's more, the coauthors of Between Women: Love, Envy and Competition in Women's Friendships (Viking, $17.95), a recently published book that has touched off a reexamination of the subject, contend that women's friendships are more bitter today than a generation ago.

Eichenbaum, 35, and Orbach, 41, have experienced their own ups and downs in 16 years of friendship. In many ways, they epitomize women's friendships today: They are both married, they share an avid interest in each other's careers and they have children who are also friends. More unusual, for the past few years they have lived an ocean apart (London and New York); and yet, they claim, the friendship is stronger than ever.

"Our phone bills are atrocious," says Orbach in an interview. "But it's a necessity; we have to talk."

Talk seems to be the essence of women's bonding. Defining and distinguishing women's friendships, as an "easy reciprocity ... allowing so many things to be safely discussed and felt," the authors say that although society only recently has recognized women's friendships as valuable (historically, friendship was seen strictly between men), they have always been so.

Women are comfortable talking to each other, says Orbach, "about everything from their personal sex life to their deepest hopes, fears and fantasies."

Women not only talk, they feel each other's story as if it were their own; so there is little hesitation for either party to "open up." Molly Haley, a small business owner and consultant in Bethesda, observes, "When two business women meet for lunch, their life stories are out on the table by the first hour. It's not the same when two men meet. It's all business."

But in this post-feminist era something has drastically changed in the empathetic union of women. Eichenbaum and Orbach, in their respective practices at the Women's Therapy Centre in London and the Women's Therapy Centre Institute in New York, have found that women -- particularly those in their thirties and early forties -- experience strong feelings, such as envy, competition, anger, abandonment and guilt, with their women friends. But they are afraid to talk about these feelings directly to the friend.

Women assume, says Eichenbaum, that negative feelings which come "unexpectedly" in the middle of a seemingly comfortable relationship are "unacceptable," and are dangerous to the friendship.

These are typically women going through major and difficult role changes in the work world and at home. In addition to external pressures, such women hold high expectations of themselves and other women. Many of them work in a "man's unemotional work world," say the authors, and they believe they are "at risk for losing one's place on the ladder of success if they should show any sign of emotional vulnerability."

Consequently, as women hold back from expressing their angst, they "isolate their emotions" and themselves. In this new world of "every-woman-for-herself," say Eichenbaum and Orbach, "the old support systems can be tragically undermined."

Kathleen Gray, a Washington psychotherapist and a professor of social work at Catholic University, agrees: "Once women start playing by men's rules, they lose their feminine power." According to Gray, feminine power is defined as, "We can all win without anyone getting hurt." Masculine power means, "Every man for himself," or, as the French say, "It's not enough to succeed, your best friend must fail."

This is not to say that women are innocent of competition and wily ways. Historically, women have always competed with other women for men's love and attention, and they are well aware of the rules of what is fair and what isn't, says Gray. But women's competition today takes on an additional and new meaning. It's becoming downright dangerous, for instance, for one woman to step on another's career or her decision to have a family.

"The female's prime instinct is to protect her young," says Gray, refering to sociobiological theory, "which nowadays can be her career. She will fight any other female to do that. She doesn't do this with the male {on the job} because she still needs him to protect her career."

According to Eichenbaum and Orbach, women's friendships are threatened by events such as:

A friend's change in career or her dramatic success.

A strong, conflicting stand in the workplace by a friend.

A friend's involvement with husband or lover.

Pregnancy -- the envious friend is still ambivalent about getting pregnant or has waited too long to make it feasible or safe.

One friend's super powers at balancing job, family and marriage, while the other friend feels she is barely managing.

A friend's heavy work load and inability to "keep up" with a friendship.

It may be simpler when women friends are upset over a forgotten birthday or an unkind remark. Those are the kinds of hurts women felt and commiserated over a generation ago -- and unquestionably, still do today. But such tiffs do not mark a change in women's roles and rarely destroy an established friendship.

Eichenbaum and Orbach believe the bitter and the sweet between women friends have their roots in childhood. "Women's desire for love, acceptance and support from each other," they say, "begins with their very first relationship with a woman -- mother."

Because mother and daughter share the same gender, the role of caretaker and nurturer is easy to emulate. But that rarely happens smoothly. Mother comes with her own complexity of circumstance and needs, and her own history with her mother. So no matter how good the child or how strong the child's needs, a mother can't always be as loving and responsive as her child would like her to be.

A woman who was disappointed and confused by unmet expectations of her mother, say the authors, "may unconsciously look to a woman friend to provide whatever she didn't get from her mother." When her close friend becomes involved with a new baby or new lover, or makes an unequivocal decision on a job they share, she feels abandoned, diminished or enraged. Yet she can't freely express the rage, or even speak up and talk directly to the friend, say the authors, for fear of losing her friend who is important to her and crucial to her self-identity.

Disappointment in mother and fear of her rejection is an age-old fact of women's psychology. But there is a contemporary aspect of the early mother-daughter relationship -- autonomy versus attachment.

Women often unconsciously resist success and autonomy because, as little girls, they "grow up learning that knowing what others want, caring for them and being attached to others" is the right way to be, explain the authors.

At the same time, girls (not boys) learn that "taking initiative and seeking a separate identity is wrong ... "

This doesn't stop women in their adult life from seeking autonomy and separateness, say Eichenbaum and Orbach. But it does load any such attempts with guilt and confusion. "Women can sabotage each other" says Eichenbaum, "by not letting each other grow in independence."

This especially holds true in negative, or commiserating friendships, where the strength of the two women's bond lies in complaints -- typically about men or a job. If one friend shows some independence in changing or in questioning her friend's or her own negative attitude, the friendship may collapse. In this case, say the authors, it is healthier for such women to go their separate ways.

Independence also threatens the positive friendship. A 45-year-old woman executive in the Washington offices of a major corporation established an intimate friendship with another woman executive in the company's Dallas offices. The distance meant nothing in their jet-paced life and their bond was deeply emotional.

"Three years ago I was recovering from my father's death," explained the Washington woman, "when this woman's father also died. We became very close by helping each other through it ... " They remained good friends until a year later when the Dallas woman was having serious trouble in her department with the "head honcho," a man who was on good business terms with the Washington woman.

"She wanted me to go to him and get him to make major changes in her department," recalls the Washington woman. "But I felt this should not be a triangle communication. It did not involve my department and she had to deal directly with him."

As colleagues watched, the friendship between the two women ended abruptly and with no words. "She has closed the door on me," says the Washington woman, "I could hear it. She refuses to deal with me.

"The friendship is over not because we were emotionally close and the business relationship couldn't handle it, but because I took a strong stand and she can't confront me with her anger."

Eichenbaum and Orbach say that, realistically, women today can't be expected to totally eliminate their negative feelings toward one another, but they can learn to express those feelings.

If the friendship is worthwhile, it should survive a thoughtful confrontation. Don't yell at your friend, says Eichenbaum, but take a strong stand and talk it out. "If women don't periodically bring up their difficulties with one another," say the authors, they will "remain stuck in a merged attachment or their relationship becomes fractured."

Gray emphasizes that "women need to get more in touch with their feminine power again. They can still be nurturant caretakers as well as assertive. They don't have to play by men's rules. They can make their own rules."

Although openness is part of that feminine power, it doesn't always come easy. A Baltimore woman in her early thirties says that when she was working in a Midwest hospital several years ago, she was asked to give an opinion on a co-worker's performance. "She wasn't just a co-worker," recalls the woman, "she was my good friend and neighbor. We were friends all through college.

"My opinion got back to her and she was very upset. What was admirable was that she confronted me with it. I admitted to it and apologized. I told her I didn't mean it to be derogatory.

"But the friendship remained strained. We were cordial to each other, but it was never the same. She knew I violated the friendship. From that time on I have never done that again with any woman."

Many women feel safer talking about their angst with an "outside" party -- another woman. But this, Eichenbaum and Orbach say, only serves to dilute the original friendship and undermines any possible autonomy. A 46-year-old woman says that she "felt horribly guilty" about complaining to other women about a close friend's constant criticism of her managing her family and career.

"I finally stopped gossiping to others and openly confronted my friend," she says. "It was not a pleasant experience. She first denied what I was talking about, but the more we talked, she came through. She didn't apologize, but she let me say what I felt. We are better friends for the whole experience."

Unfortunately, Eichenbaum and Orbach's book concentrates mainly on women who have just one very close friendship, as well as some triangle friendships. It doesn't cover women who have numerous friendships -- a well-known phenomenon that eases tensions and spreads out the positive energy that exists between women.

Therapist and author Lillian Rubin, in her 1985 book Just Friends, points out that, as women's roles and needs change over the years, it is possible to add new and rewarding friendships without losing or diminishing old friendships. "One {friend} calls upon our nurturant, caretaking qualities," writes Rubin, "another permits our dependency needs to surface. One friend touches our fun-loving side, another our more serious part. One friend is the sister we wished we had, another offers the mothering we missed."

"The problem with having just one friend, is that she's not always there," says Anne Crossman, Washington writer who is single and feels "blessed" having both married and single women friends.

"To concentrate just on one wouldn't be fair to me or to the others. I have a wonderful mix of women friends, so I don't have any trouble with them."

Like Crossman, not all women would agree with Eichenbaum and Orbach's gloomy premise on the increasing tensions between contemporary women.

A 44-year-old Milwaukee housewife says she doesn't have "any patience" with this concern of envying and losing women friends.

"I worried about those things when I was in my twenties," she says. "Now I can get mad at my friends, but it only lasts a day and they still know I'm loyal."

Nor does Pat Spector consider it an issue in her life. "My sense is while we have unrealistic expectations with men, we tend to be realistic with women," says the 44-year-old Washington schoolteacher. "We accept the flaws of women friends much more gracefully. Our doing that doesn't diminish the friendship, it makes the friendship last." But it is a major issue in the lives of two women who have been "close, close friends" and business associates for more than 15 years and are now facing the possible close of their company. Their friendship is in jeopardy over the loaded emotional dilemma of one friend seeing the other as "out only for herself."

"I'm not sure how this happened or what the resolution will be," says one of the women who asked not to be named. "I have tried to talk to her about it, but for some reason it takes a lot of nerve and is very hard for me to do.

"I had always thought it was good to be empathetic, but our being so close, this time, works against us."