In a breakthrough for long-stalled tobacco legislation, the Senate last night overwhelmingly approved a newly struck deal to regulate the manufacturing, marketing and sales of cigarettes in return for an industry-financed buyout of tobacco farmers.

Despite the 78 to 15 vote in favor of the Senate proposal, its backers cautioned that it could get derailed in negotiations over the huge, complex and controversial corporate tax relief bill to which it is attached. Some House Republican leaders favor the buyout but oppose government regulation. Key lawmakers have indicated uncertainty over whether the bill can be completed this year.

But supporters of the deal, representing anti-tobacco forces and tobacco-producing states, said it embodied the best chance to win approval for their respective initiatives.

It was the first time that either house approved the regulation of tobacco by the Food and Drug Administration, according to a coalition of public health groups. It was also the first time that major tobacco legislation appeared to have a good chance of passage since an ambitious tobacco control bill collapsed in 1998.

"I think we have a good shot at this becoming law," said Sen. Mike DeWine (R-Ohio), who co-sponsored the regulation proposal with Sen. Edward M. Kennedy (D-Mass.). "The bill will save lives," he added.

The proposal would give the FDA broad authority to regulate the sale, distribution and advertising of cigarettes and other tobacco products -- aimed at reducing smoking and addiction by children and teenagers, according to its sponsors.

Among other things, it empowers the FDA to bar industry advertising aimed at children, end vending machine and self-service sales, require stronger and more conspicuous warning labels, bar or limit the use of hazardous ingredients in cigarettes and prohibit "reduced risk" health claims if they cannot be verified.

Tobacco companies would have to give the government a list of all the ingredients and additives in tobacco products, along with any new documents relating to the health and other effects of tobacco use. The FDA could require that ingredients be listed on the products.

The FDA could also require changes in tobacco products, such as the reduction or elimination of additives, but it could not ban the products themselves without congressional authorization, which appears unlikely at this time.

These proposals go far beyond current government regulations, which are limited largely to advertising constraints and health-warning labels, DeWine said. The FDA tried in the mid-1990s to expand its regulation of tobacco but was stopped by the Supreme Court, which found that it lacked the power under existing law.

Under the buyout proposal, the tobacco industry would pay farmers to abandon a quota system -- aimed at limiting production and bolstering prices -- that dates back to the 1930s but has since lost much of its value to individual farmers.

Manufacturers of cigarettes and other tobacco products would be assessed $12 billion over 10 years to finance the buyout, with each company's contribution pegged to its market share.

The cost is likely to be passed on to smokers and could increase the price of cigarettes by about 6 cents a pack, according to congressional aides.

The deal arose largely out of the fact that the buyout plan, a political "must" in tobacco-producing states, appeared doomed without the backing of tobacco foes who were demanding more government regulation as the price of their support.

It was a "shotgun marriage . . . that made sense," DeWine said. "It's not a shotgun wedding; it's a marriage of convenience," said Senate Majority Whip Mitch McConnell (R-Ky.), a leading buyout backer.

Like McConnell, Sen. Jim Bunning (R-Ky.) said he is opposed to the government regulation of tobacco but is willing to accept it as the price of a buyout. "I think FDA regulation is a very steep price to pay for a buyout," Bunning said. "But if that's the only way to get my growers relief, this senator will vote to pay it."

The House had approved a government-financed buyout but later withdrew its support for government financing. Its bill did not include FDA regulation, which is less popular in the House than it is in the Senate.

Pressure is strong for the approval of the tax measure because the European Union is levying tariffs on U.S. exports until the United States replaces the export subsides outlawed by the World Trade Organization. But the legislation includes costly special-interest provisions and other features that may be difficult to deal with.

The Altria Group Inc., parent company of Philip Morris, has endorsed the regulation proposal, but other large tobacco companies oppose it. R.J. Reynolds Tobacco Co. issued a statement yesterday saying the deal "fails to make U.S. tobacco farmers more competitive and would be financially disastrous for tobacco manufacturers, their employees, their business partners and adult smokers, many of whom are lower- and middle-income wage earners."

In yesterday's vote, all Washington-area senators voted for the proposal.