LOS ANGELES, NOV. 13 -- Letting teachers share in decision-making, the principal American school reform of the late 1980s, is off to a rocky start in the country's second-largest school district, according to a new report by the Los Angeles city school board.

The board's independent analysis unit reported that sharp differences have weakened the reform, instituted last year as part of the district's teacher contract after a bitter nine-day strike. These involve student discipline, funding cutbacks and "hostility and distrust" so deep that some teachers refuse to call their school's leader "principal," it said.

The controversial 29-page report insisted that "it is premature to determine whether the innovation has been successful." But the results have rocked confidence in the program here and statewide at a time when most of the nation's school districts appear to be considering similar changes in management and teacher power-sharing.

Helen Bernstein, president of United Teachers-Los Angeles which helped to create the "Shared Decision Making" plan, vehemently criticized the report and said it represents the work of administrators trying to strangle the program in its infancy. "I'm absolutely horrified," she said. "I think the whole thing is bogus."

Bernstein said school officials rejected union pleas to give the program more time before the initial evaluation and broke a promise not to publicize the result. She said at least five of the 10 schools sampled in the report had poor teacher-principal relationships long before the program began.

She said a national union leader, hearing of the report, suggested that the union stop the program to avoid poisoning efforts in other cities. Some teachers, she added, called to say they wanted to drop out of the effort "because they now felt like they were wasting their time."

Shared decision-making and its companion reform, school-based management, have begun in various forms in New York, Chicago, several districts in the Washington area and many other parts of the country.

"In some places, it is doing well and in some places not," said John Yrchik, research specialist with the National Education Association. Frank Petruzielo, an associate superintendent in Dade County, Fla., said 147 of 290 schools there have embraced the program, with subsequent decreases in teacher turnover and student absences although student achievement has not increased sharply.

The Los Angeles report emphasized that "confusion in 1989-90 about a principal's proper role under Shared Decision Making may have impeded the reform's initial success."

It said some principals were intimidated into approving teacher-drafted plans for school-based management, which would give individual schools more control over budgets and schedules, although they did not meet terms of the contract.

It said teacher-union representatives in turn were so alienated that "they expressed their enmity by refusing to use the term 'principal' to describe the school's leader, instead referring to him/her as the 'administrator.' "

Critics of the plan have suggested that it would impair principals' ability to run schools because the plan gives decision-making power in five areas to local school leadership councils, with half the seats reserved for teachers. The areas are budget, discipline, equipment, scheduling and staff development.

Supporters have contended that resourceful principals can use the plan to unite faculties behind academic reforms that will improve student achievement.

The report said principals and local school leadership councils, which also include parents and administrators, clashed most often in the early months on discipline. Several councils created detention rooms and established rules making it easier for teachers to remove disruptive students from class.

The report said many teachers were "frustrated and angered" by what they thought was principals' lack of interest in their desire "for an orderly classroom in which effective teaching can take place."

There also were differences about use of copier machines, with some councils giving teachers easier access despite principals' concerns that this would increase costs and encourage teachers to rely on drills and multiple-choice tests rather than "creative teaching," the report said.