WASHINGTON - Democratic leaders negotiating a compromise health care bill appear likely to reject a House provision requiring employers to offer generous coverage to their workers or else pay a steep payroll tax, specialist say. The handful of moderate Senate Democrats who hold the political upper hand in shaping the final bill are expected to insist on the Senate's more lenient approach, which does not include a strong requirement that employers offer coverage. 'I think that the House structure ... will not fly in the Senate, given that they need 60 votes for the bill,' said Robert Greenstein, director of the Center on Budget and Policy Priorities. Killing off the strong employer mandate in the House version would represent a substantial victory for business lobbies, who last year confronted the possibility that large Democratic majorities in the House and Senate could stick businesses with heavy regulations and fines. Several influential business groups remain hostile to the Senate bill even so, but moderate Democrats have set their sights on at least keeping the Business Roundtable, a group representing large corporations, from not actively campaigning against the final bill. John Castellani, president of the Business Roundtable, called the Senate employer regulations 'a much better approach.' He said they would give firms more flexibility in what kind of insurance they offer. 'You don't want to lose the ability to be creative and innovative, to drive better care, and to lower the cost trajectory,' he said. But liberals and union leaders warn that the Senate's approach would not strengthen coverage for many Americans who already have insurance, because unlike the House bill it would not set minimum standards for health benefits for large employers with more than 100 workers. Americans will want to know, 'Is it going to stop this trend where employers are charging me higher premiums for skimpier coverage, or is it going to allow it to continue?' said Richard Kirsch, director of Health Care for America Now, a coalition of liberal groups. In the coming weeks House and Senate leaders will meet to reconcile the differences between the health bills that each chamber passed last year. The employer responsibility issue has been overshadowed by noisier debates over abortion, taxes, and the public option. While the final product will require most individuals to obtain insurance, Democrats must now decide what employers' obligations should be. A spokesman for House Speaker Nancy Pelosi had no comment on the negotiations. About 56 percent of private firms offered coverage to employees in 2008, according to the Kaiser Family Foundation. Under the House bill, all firms with more than 50 workers would have to make substantial contributions toward relatively generous insurance for employees - including part-time workers, adjusted for hours worked - or face stiff financial penalties of up to 8 percent of payroll. The Senate bill would impose smaller fees on businesses that do not offer affordable insurance if their workers sought government-subsidized coverage. Unlike the House bill, it would exempt employers from having to insure employees working less than 30 hours a week. And the Senate proposal would not dictate what kind of coverage employers must provide. Massachusetts had a similar argument over employer responsibility when it debated its landmark health care law in 2006. State lawmakers ultimately rejected a stiff payroll tax on employers that failed to offer insurance and instead opted to require firms with more than 11 employees that did not meet very basic obligations to provide insurance to pay a $295-per-employee fee. Groups on the left are still holding out hope for tougher employer provisions. Liberals have already been foiled in their efforts to establish a government-run insurance option and to kill a proposed excise tax on expensive insurance plans. 'We have to have a situation where, if the House is giving up cherished provisions like the public option, the trade-off is measures that really will help make good health care more affordable for the American people,' Kirsch said. The House bill would raise $107 billion more in fines from employers than the Senate bill over 10 years. Kirsch and others are also making the argument that the additional money could provide more generous subsidies for those who do not get coverage through work. Labor leaders are zeroing in on part-time workers, contending that the Senate proposal, by exempting employers from responsibility for employees working less than 30 hours a week, would encourage employers to cut workers' hours or hire part-timers instead of full-timers. 'Clearly if we don't win this argument, it's going to have the net effect of not getting health care coverage to ((part-time workers)) unless they qualify for Medicaid,' said the Service Employees International Union health care chairman, Dennis Rivera. But business groups say employers cannot afford heavy-handed new regulations in the middle of a downturn - businesses typically hire part-timers at the outset of a recovery. The groups also say the marginal cost of providing health insurance does not dictate hiring decisions. 'That's not how employment decisions are made,' said Castellani. 'Employment decisions are based on whether or not there is sustained demand for a product or service.' But Greenstein said he thought the part-time worker issue was one area where the Senate might budge a bit. 'A number of people are raising that issue that under Senate structure, if a firm is able to move people currently employed 30 hours a week to 29 hours a week, that it can escape having to pay much of anything,' he said. Amanda Austin of the National Federation of Independent Business, the main small business lobby, said that the main problem facing small employers is cost, and that neither the House nor the Senate bill does enough to constrain health care cost growth. If premiums are not affordable, she said, employers will face having to pay a penalty or go out of business. 'This is heavy-handed on coverage and lacking in cost-containment, which is what we're afraid of,' she said. 