Six congressional leaders in the health field launched yesterday the most serious effort since the late 1970s to provide health insurance for 37 million uninsured Americans, proposing a bill backed by a large group of health organizations.

The bill -- sponsored by Sens. Edward M. Kennedy (D-Mass.), David F. Durenberger (R-Minn.), John Heinz (R-Pa.) and Don Riegle (D-Mich.) and Reps. Fortney H. (Pete) Stark (D-Calif.) and Willis D. Gradison Jr. (R-Ohio) -- is not comprehensive national health insurance, Kennedy emphasized, but a series of piecemeal steps to address the coverage problem.

The bill would require the states to set up insurance pools to offer coverage to people who do not have it at work, with premiums no more than 1.5 times the normal rate for individual policies, regardless of health history.

It would require states to pay hospitals for $5.7 billion they provide annually in charity care and uncompensated care.

The bill would require employers to continue health insurance for laid-off workers and their dependents for four months. After that, the workers could extend coverage for another 18 months by paying the premiums themselves.

It would give owner-operators of unincorporated small businesses tax deductions for their own health insurance premiums. They now get deductions for their workers but not themselves.

Stark, who heads the House Ways and Means health subcommittee (Gradison is the senior Republican), and Durenberger, who heads the Senate Finance health subcommittee, said they might attach the bill to a budget reconciliation measure -- a strategy they used to pass hospital "anti-dumping" legislation.