A compromise bill on the future of the chronically troubled St. Elizabeths mental hospital passed its first congressional hurdle yesterday, and House members said they would put the measure on a fast track in hopes of getting it all the way through Congress this year.

The House District subcommittee on fiscal affairs approved the bill, which would transfer responsibility for the huge 127-year-old institution from the federal government to the District government over a six-year period ending in October 1991.

Under the plan, federal financing of St. Elizabeths would end in 1991, but the subcommittee added language yesterday that says Congress will "consider" continuing some funding after that date.

"It's going to be difficult for the city to absorb $50 to $100 million in hospital costs without some assistance" beyond 1991, said D.C. Del. Walter E. Fauntroy, the subcommittee chairman, before offering the language.

After the legislative markup session, Gladys W. Mack, director of the D.C. office of policy and program evaluation, said the added language means the city now probably can support the measure as approved by the subcommittee.

The federal and city governments have been at odds for years over how and when to transfer St. Elizabeths and how much funding the federal government would provide. The hospital has faced a series of financial crises, with Congress stepping in at the last minute to bail it out with special funding.

The bill would require the city to have a comprehensive system in place by 1991 to take care of an estimated 6,000 persons in the District who need mental health care. There now are almost 1,800 inpatients at St. Elizabeths in Southeast Washington, and other persons receive treatment at community facilities run by the city.

The compromise bill was developed after negotiations with the U.S. Department of Health and Human Services, the District and the main hospital employes union.

Representatives of each of these groups yesterday asked the subcommittee to make changes, but only a few were adopted. One change provides more protections for current hospital workers, ensuring their seniority and giving them first shot at jobs with city contractors providing mental health services.

The panel killed plans for a special nine-member commission that was to have authority to amend and approve the city's comprehensive plan. Instead, the House District Committee and the Senate Governmental Affairs Committee would have to approve the plan.

The full committee is scheduled to consider the bill next week, and the panel hopes to get House approval on Sept. 17. The Senate then would have less than three weeks before the scheduled end of Congress to act on the measure.