WASHINGTON (Reuters) - U.S. President Barack Obama’s push for healthcare reform gathered steam on Thursday as a Senate panel scheduled a key vote for next week and Democrats in the House of Representatives moved closer to unveiling a bill.

President Barack Obama looks at brain cells through a microscope during a tour of an oncology laboratory at the National Institutes of Health in Bethesda, Maryland September 30, 2009. Standing over Obama is Dr. Marston Linehan. REUTERS/Kevin Lamarque

The Senate Finance Committee will vote on Tuesday on its healthcare plan after budget analysts gave the bill a rosy report card, estimating it would meet Obama’s goal of reducing the budget deficit over 10 years.

The non-partisan Congressional Budget Office put the cost at $829 billion, below Obama’s $900 billion goal, in a report on Wednesday that cleared the way for likely committee passage and an eventual debate in the Democratic-controlled Senate.

Republicans, concerned about the bill’s costs and potential impact on the budget deficit, had demanded the estimate before they cast a vote on the proposal to dramatically transform the $2.5 trillion healthcare system.

“Today we stand closer than ever to fulfilling that fundamental promise, the one for which we have fought for more than 60 years,” Senate Democratic leader Harry Reid said of healthcare reform.

Obama’s healthcare drive, his top domestic priority, is aimed at cutting costs, regulating insurers and expanding insurance coverage to millions of Americans without it.

Shares of large health insurers slumped on Thursday as the CBO report fueled investor fears an overhaul that would damage the industry was headed for eventual approval.

Once approved by the Finance Committee, Reid and other party leaders will merge the panel’s bill with one passed by the Senate health committee earlier this year for Senate consideration.

Republicans said the merger would reshape the bill again, and some disputed its calculations and said the actual cost would be much higher. Senate Republican leader Mitch McConnell labeled the CBO report “irrelevant.”

“What matters is that the final bill will cost about a trillion dollars, vastly expand the role of government in people’s healthcare decisions, increase premiums and limit choice,” he said.

OBAMA “FISHING” FOR SNOWE

Senator Olympia Snowe, the lone Republican on the committee considered a possible supporter of the measure, said she had not decided how to vote but talked with Obama on Thursday.

“What do you think he wants?” she joked to reporters. She said Obama was “fishing” for whether she would back the bill.

Obama has staked much of his political clout on the healthcare drive, and failure could derail the rest of his legislative agenda and weaken his fellow Democats in next year’s congressional elections.

In the Democratic-controlled House, where party leaders have met for weeks to meld three pending bills into one for debate, House Speaker Nancy Pelosi said they were nearing their final decisions.

She said they would get cost estimates from CBO on a bill with three options for a government-run “public” insurance plan, which Obama and liberal Democrats support as a way to inject competition into the insurance marketplace. Critics say the approach would hurt the private insurance industry.

All three pending House bills include a public option, which Pelosi said was backed by a majority of the House. “Now it’s a question of which one,” she told reporters.

One House version would be based on reimbursement rates paid to healthcare providers under Medicare, the government-run health plan for seniors, and the other two would rely on reimbursement rates negotiated with the providers.

House Democrats agreed to adjust a proposed surtax on the wealthy to ensure it would not apply to individuals making less than $500,000 or couples making less than $1 million, a Democratic aide said.

The proposal would raise about $460 billion over 10 years -- about $84 billion less than originally proposed.

Pelosi said Democrats also were looking at the possibility of a windfall profits tax on insurance companies’ income, and she had asked House Ways and Means Committee Chairman Charles Rangel to examine the issue and report back to her.

Pelosi said insurance companies would get millions of new consumers, many subsidized by taxpayers, under the reforms and “We think they can put more on the table.”

Shares of health insurer WellPoint Inc fell more than 6 percent, while UnitedHealth Group Inc, Aetna Inc and Humana dropped more than 3.5 percent as investor grew nervous about the reform drive.

“The successful CBO score increases the likelihood that a reform bill will pass,” Wells Fargo analyst Matt Perry said.