The Maryland Legislature gave final approval yesterday to a first-of-its-kind bill that takes aim at Wal-Mart and is strikingly similar to a law passed late last month by the New York City Council.

The legislation – which was passed when both the Democratic-controlled Senate and House of Delegates overrode vetoes by Governor Ehrlich, a Republican – requires companies in the state with more than 10,000 employees to pay a portion of their employees’ health care costs.

The vote, which comes about a month after the New York City Council passed the so-called Health Care Security Act, sets the stage for a national showdown centered on whether local and state municipalities have the authority to dictate what benefits private companies must pay. Unions, lobbyists, and other lawmakers in the country have been closely watching things unfold in Maryland.

The head of the Maryland Citizens’ Health Initiative, Vincent DeMarco, told Bloomberg News that it was a “great moment for working families in Maryland” and predicted that similar measures would “sweep the nation.”

Opponents said it will cost the state jobs and is a direct swipe at Wal-Mart, the low-cost retail giant that has resisted labor’s attempt to unionize its employees. The company has 17,000 employees based in Maryland and is the only company that will fall under the legislation’s umbrella.

A spokesman for Wal-Mart, Nate Hurst, told the news wire that because of the law’s passage, the company would now rethink its plan to open a distribution center in the state that would employ 800.

“Maryland legislators shouldn’t be putting these jobs at risk by making laws that attack Wal-Mart,” Mr. Hurst said.

When the City Council here passed its bill, Mayor Bloomberg vetoed it and argued that it violated the federal Employee Retirement Income Security Act. Mr. Bloomberg said the city should work to reduce the number of uninsured in the city, but that local legislation was the wrong approach. In his veto message, he predicted that it would lead to “a distracting and time-consuming legal fight.”

Yesterday, the council’s new speaker, Christine Quinn, who was the lead sponsor of the bill here, hailed the Maryland Legislature’s move.

“I applaud their commitment to health care and workers’ rights,” she told The New York Sun during a phone interview last night. “We’ve now seen Nassau, New York City, and Maryland do this.”

“I think and hope this will be a trend in cities and states across the country,” she said. “The more that county and state legislatures take action, it certainly erodes the argument that this action can only be taken by the federal government.”

The council’s bill applies to stores that meet certain square footage requirements and have a certain number of employees. The 51-member body passed an amended version of its bill to exclude small and medium-size supermarkets because owners argued that they would be financially devastated if they had to provide the benefits.

If it stands up to legal challenges, it will require affected stores to pay about $2.75 an hour for each of its employees.

Supporters of the city law said the legislation will secure health insurance for thousands of New Yorkers, protect competing businesses that already contribute to their employees’ medical expenses, and save taxpayer money by shrinking the public health insurance dole.

Opponents of the council bill had a different take. One health care economist, Charles Brecher, said it was bad policy to target one industry because it haphazardly put certain businesses at a competitive disadvantage. Others said it was a union-devised strategy to block Wal-Mart from opening in the five boroughs.

Yesterday, Council Member Andrew Lanza, a Republican from Staten Island, said he was “troubled” when elected officials respond in overreaching ways to “pressures from special interests.”

“At the end of the day, this is America,” Mr. Lanza said. “It’s a capitalist democracy. We have a free market.”

He called the council bill, which he voted against, a “transparently hypocritical and dishonest measure” aimed at making it more difficult for Wal-Mart to open here.

More than 30 states are said to be considering similar legislation.