The strike between the secular studies teachers and the suburban Detroit Jewish parochial school had lasted three weeks. It had become acrimonious with a host of issues and no end in sight.

What ended it finally last year was not a settlement but the promise of one, to be arrived at without resort to the civil courts but according to the tenets of both secular and religious law.

The surprising peace-makers were three Orthodox Jewish attorneys from Washington -- one of them an ordained rabbi -- operating as P'Shara, a unique mediation service for settling disputes between Jews.

In this binding arbitration, both sides won some and lost some -- and both were satisfied.

"We had gotten to the point where we couldn't communicate with each other, which is why we brought P'Shara in," said secular teacher Susan Colbert.

In its lengthy, 40-page opinion, the mediation panel cited both civil cases and rabbinical rulings in support of its own Solomonic solutions.

In other instances, P'Shara has taken a similar approach in mediating a nasty divorce and settling a severance pay dispute between employer and employee.

"The idea is to keep the dispute within the family," said Ira Kasdan, president of P'Shara.

While civil and religious laws do not always differ, Orthodox Jews are discouraged from resorting to secular tribunals to settle disputes with other Jews.

In Europe, rabbinical courts known as bait din, or houses of judgment, decided disputes. In this way, a whole body of written Jewish religious law has evolved over the centuries.

In the New York area, the Jewish Conciliation Board of America uses panels of lawyers, rabbis, businessmen and others to settle disputes.

Washington has no such religious court or Jewish conciliation board, but it has 54,000 lawyers, some of whom mediate or arbitrate disputes.

The D.C. Superior Court has its own dispute resolution service, which keeps about 4,000 cases a year out of court.

And then there is P'Shara, Hebrew for compromise. Jewish Dispute Resolution, Inc., its corporate name, was started a year ago by three Jewish lawyers, who also continue to work at other jobs.

Except for the yarmulkes they wear on their heads, they appear indistinguishable in their conservative suits and tasteful ties from other uptown lawyers.

There is Rabbi Avrom Landesman, 55, a former deputy counsel to the U.S. Department of Energy, who won a $1.5 billion antitrust settlement against big oil companies before retiring in 1986 to private practice in Silver Spring.

Kasdan, 37, is a partner in the Connecticut Avenue law firm of Ginsburg, Feldman and Bress. Also at Dispute Resolution Inc. is Edward Tolchin, 33, who is leaving the Ginsburg firm, where he is also a partner, to start his own firm.

Both Kasdan and Tolchin graduated from Yeshiva University and Georgetown Law School.

Landesman has a law degree from Harvard University and his ordination from Yeshiva Torah V'Daath in New York.

P'Shara also has an outside rabbinical advisor, Silver Spring Rabbi Irving Breitowitz, who has a Harvard Law degree and teaches law at the University of Maryland.

He is also the rabbi of the Woodside Synagogue.

"The rule against Jews suing Jews in secular court is widely ignored in practice," Breitowitz said. "That's one of the reasons P'Shara came into existence. The concept is by not resorting to Jewish procedures, one is denigrating the validity of those procedures -- a desecration of our faith."

Said Landesman, "In fact, "ecclesiastical law is encompassing enough to handle most disputes."

For their services, they charge a one-time "administrative fee" of $100 plus expenses and $180 an hour each.

Citing client privilege, they declined to discuss specifics of their cases or to identify the parties, except in the Detroit dispute, which was reported in the local Jewish press.

Their penchant for protecting the privacy of their clients extends even to promotional literature, which contains three anonymous testimonials.

But principals in the Detroit dispute were anything but shy in praising P'Shara for their role at Yeshiva Beth Yehudah, a 75-year old school with 650 students, 40 secular studies and 80 Hebrew teachers.

The secular teachers and the administration had failed to reach agreement when the old contract expired in September, 1989, despite four months of meetings. The teachers continued to work without a new contract until last May, when they struck.

"It was extremely acrimonious," said Rabbi E.B. Freedman, the school administrator. "We're not talking violence, but we were seriously deadlocked."

The two sides were divided on 13 issues, he said, prominent among them parity with the higher-paid Hebrew teachers. Enter P'Shara.

Over the summer, the P'Shara team held two sessions with the parties, working from early in the morning to late at night.

"A lot of Hebrew words were being tossed around," Tolchin said. "We had to stop every few minutes to translate" for the teachers' non-Jewish lawyer.

The school had a Jewish lawyer. Both sides submitted lengthy briefs.

On whether the teachers should be paid for their time on strike, P'Shara took into account an affirmative ruling 30 years ago by a rabbi in an earlier dispute at the same school.

But a more recent rabbinical opinion in another case persuaded them not to grant it.

The teachers did not achieve parity but they made wage gains.

"We can certainly live with the product we got from P'Shara," said Colbert, who teaches English to Soviet Jewish immigrant children.

"So far, we've had no major arguments. The big plus is we have a contract."