WASHINGTON - The Senate Finance Committee battled over insurance plans for seniors on Wednesday and rejected a Republican effort to delay a final vote on a broad healthcare overhaul as it slowly waded through a crush of amendments.

Demonstrators protest in front Blue Cross offices in downtown San Francisco, Tuesday, Sept. 22, 2009. The demonstrators are protesting Blue Cross' opposition to a public health insurance option as part of a health care reform package. (AP Photo/Paul Sakuma) Democrats, the majority party in the Senate, repeatedly dismissed Republican proposals on a series of largely party-line votes through a long day that barely made a dent in the hundreds of pending amendments to the proposal by Chairman Max Baucus.

Democrats defeated Republican efforts to spare cuts in some areas of Medicare, the government-run insurance program for the elderly, and rejected a controversial measure sparked by the probe over a letter from insurer Humana Inc. to its customers.

Republicans also demanded more information on the bill's budgetary impact and called for the Democratic-controlled panel to slow its deliberations on the reform plan, which Baucus had hoped to bring to a final vote this week.

Democrats said the requests were a tactic to stall President Barack Obama's top domestic priority, a broad overhaul of the $2.5 trillion healthcare industry that would rein in costs, regulate insurers and expand coverage to many of the 46 million uninsured people living in the United States.

The panel, which has a 13-10 Democratic majority, rejected a Republican effort to delay a final committee vote until the bill could be put into legal language and posted on the Internet, and budget experts could estimate its full cost.

Baucus said Republican Senator Jim Bunning's proposal would create at least a two-week delay as the Congressional Budget Office completed its final analysis of the bill.

'WHAT IS THE RUSH?'

"If it takes two more weeks, it takes two more weeks," said Senator Olympia Snowe, the only panel Republican considered a potential supporter of the final bill. "We're talking about trillions of dollars in the final analysis. What is the rush?"

Instead, the panel approved Baucus's pledge to post a preliminary CBO cost estimate on the committee website before a final vote -- a step that makes it highly likely a final vote will spill over to next week.

The Baucus plan is the last of five bills pending in Congress on a healthcare overhaul that has been slowed by intense political skirmishing and criticism from all sides.

In one of the day's sharpest exchanges, the panel rejected a Republican effort to keep the agency that administers Medicare from interfering with contractors that express their views about the healthcare bill to their elderly customers.

The amendment was inspired by the probe over Humana, which contracts with the government to provide insurance through Medicare Advantage, a program that augments the public plan with private insurance.

Humana sent a letter to its participants warning that the reform bill would mean "millions of seniors and disabled individuals could lose many of the important benefits and services that make Medicare Advantage health plans so valuable."

The Centers for Medicare and Medicaid Services began an investigation and described the mailings as misleading. Health insurers called it a gag order, and committee Republicans said it was a free-speech issue.

Democrats said it had little to do with constitutional rights and more to do with corporate responsibility, given the access to personal information the insurers could obtain through government contracts.

Democrats also defeated a Republican amendment to ensure the bill did not result in benefit reductions in the Medicare Advantage program. Republicans say program participants could lose some benefits under the bill because of the its reduced payments to the plan's private insurers.

The committee accepted without objection an amendment reimbursing doctors for prescribing biogeneric or biosimilar drugs at an additional six percent over the competitive rate.

The S&P Managed Health Care index of large health insurers' stock prices fell for a second straight day as several analysts said the amendments to the Baucus bill were generally unfavorable to the industry.

Under the Baucus plan, all U.S. citizens and legal residents would be required to obtain health insurance, with subsidies offered on a sliding scale to help people buy it. The plan would create state-based exchanges where individuals and small businesses could shop for insurance.

It does not include a new government-run insurance program -- the "public option" -- that would compete with private insurers. That is included in the other four healthcare bills in Congress and is backed by Obama and liberal Democrats.

The insurance industry and some drug makers have lobbied against the healthcare overhaul and in particular the public option. Senate Democratic Leader Harry Reid said Congress should stand up to them.

"We have got to show the American people that we can overcome the power of the insurance industry and the pharmaceutical industry. That's what it's all about," he said.

(Editing by David Alexander and Will Dunham)