The director of an embattled $41 million pilot program for the rehabilitation of inmates at the Lorton Reformatory intends to resign from her post with the D.C. Department of Corrections, Mayor Marion Barry disclosed yesterday after taking part in a congressional hearing on the program.

Barry said that Margaret Labat, assistant director for educational services, "is on her way out by mutual agreement." She is the second director to depart since the federally financed program began in October 1983. No successor has been designated.

The program has been under fire from its chief architect, Sen. Arlen Specter (R-Pa.), and others for delays in implementation and for infighting between corrections administrators and program workers. Labat, a former assistant D.C. school superintendent, has served as head of the program since March 1984.

Specter, the chairman of the Senate D.C. appropriations subcommittee who conducted yesterday's hearing, sought a reduction later in the day in the program's fiscal 1986 budget from $6.7 million to $3.35 million, saying he intended to add more later in a supplemental bill.

He said the reduction, which was approved by House and Senate conferees working on the 1986 D.C. appropriations bill, was a "measure to keep a close track on what is going on."

The job training and education program was begun as a rehabilition-oriented companion piece to Specter's hard-line policies on incarceration and parole. The program's first director, Patricia Taylor, was replaced by Labat, and an oversight committee headed by former Watergate prosecutor Richard Ben-Veniste was formed to prod the initiative forward.

Ben-Veniste, who testified yesterday, said there was still "room for substantial improvement" in the program, but that he was "reassured that Mayor Barry was very much committed to the vocation and education initiative."

Ben-Veniste said Labat had achieved successes in raising literacy but lacked a background in correctional education and had not developed the key vocational programs.

Complaints about the program also have focused on tardiness in constructing new classroom and training areas and a failure to use expensive computer and graphic arts equipment that was purchased for the program.

In addition, some community advocates for prison jobs programs have criticized what they consider the corrections department's failure to invite participation of businesses, religious organizations and other nonprofit groups.

James D. Carroll, president of the Washington Correctional Foundation, said there has been a "substantial failure" to tie vocational training to job opportunities in the area.

Labat could not be reached for comment yesterday. However, in an interview two weeks ago, she said she initially had emphasized literacy programs as a precursor to vocational training. The department, she said, is "getting vocational programs into place."

Labat said her efforts had met with resistance from the entrenched corrections bureaucracy and that it had been difficult to coordinate the capital improvements and programming aspects of the Specter initiative.