House Ways and Means Committee Democrats chopped nearly $1 billion from the five-year cost of a major welfare-overhaul bill yesterday and dropped a provision imposing minimum benefit levels on states, hoping to beef up support in their party and among Republicans.

But Republicans, led by Reps. Hank Brown (Colo.) and Bill Frenzel (Minn.), told reporters before the committee met in closed session that the measure contains many "restrictions" on incentives to work and makes benefit changes that could discourage welfare clients from seeking jobs.

Frenzel indicated he would not support a provision that remains in the bill requiring states to provide benefits under the Aid to Families with Dependent Children program to families in which a husband is present in the home but unemployed. Frenzel said GOP members also dislike a provision raising federal reimbursements to states on any benefit increases they make.

The bill, sponsored by Rep. Harold R. Ford (D-Tenn.), was approved in subcommittee several weeks ago with a five-year cost of $6.126 billion.

In closed meetings over recent weeks, southern Democrats told Rep. Thomas J. Downey (D-N.Y.), who has taken over management of the bill, that they could not support the measure unless its cost was cut. They also wanted him to drop a provision requiring states to raise AFDC benefits to 15 percent of the state's median family income, adjusted for family size, by fiscal 1993. The minimum benefit requirement would have affected 18 states, most in the South.

After prolonged negotiations, Downey came in yesterday with a package reducing the five-year cost to $5.246 billion. It dropped the minimum benefit provision, reduced federal reimbursements to the states for AFDC administrative costs to the current 50 percent instead of the proposed 60 percent, and made other changes.

The committee adopted the package by voice vote. A vote on the bill is expected today.

Under the revised bill, states would be authorized to create broad education, job-training and work programs for welfare parents, with the federal government paying 65 percent of the cost. (The subcommittee bill had proposed 60 percent.)

In addition, the bill would require states to pay benefits to low-income two-parent families with an unemployed breadwinner. States that improve their benefit levels would receive a 25 percent increase in the share of AFDC benefit costs now paid by the federal government, but the federal payment could not exceed 90 percent of benefit costs. The federal government now pays states 50 percent to 78 percent of their benefit costs.