MADISON, Wis. -- As of Monday, most companies that contract with Dane County must offer the same benefits they offer their married employees to workers who have domestic partners.

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Dane is the only county in the state to mandate this kind of coverage and to set up a registry for it. The ordinance, which was approved by the Dane County Board of Supervisors in September, grandfathers some businesses in so the real impact of the measure won't be felt right away -- perhaps not for months or even years, WISC-TV reported.

Some businesses, like Goodwill Industries, which currently has a more than $1 million county contract for mental health services and developmentally disabled skills and job training, are setting up coverage right now, while other companies worry about their future costs.

Two years ago, banning same-sex marriage proved to be a bitter statewide debate when a constitutional amendment passed in a referendum. But now, some of those who unsuccessfully fought against the ban said that they're finding new hopes and new leadership from Dane County.

While same-sex couples still can't marry in Wisconsin, they can now register with Dane County for a domestic partnership -- and the benefits that go with it. Unmarried heterosexual couples can sign up as well, according to Travis Myren, deputy director for Dane County administration.

"The domestic partners ordinance covers both same and opposite-sex domestic partners," he said.

Under a new county Domestic Partnership Registry, anyone 18 years or older, who isn't married and is in a "committed relationship" for 90 days or more sharing the same residence, can sign up for domestic partner benefits.

The benefits would only be open to people in private businesses that secure county contracts for $5,000 or more. The ordinance requires that such businesses have to extend whatever health insurance and other benefits are offered to their married employees to employees with domestic partners.

"Whatever they have, they provide the equivalent of that to domestic partners," Myren said.

Scott Vaughn, who works with trade unions representing 4,000 construction workers and their families, said that most contractors don't know about the ordinance and that for many, it might prove unworkable.

He said this is the case because most union contracts cover multiple counties -- even the whole state. Extending domestic partner benefits just to Dane County workers is impossible, he said. . "We're not against the ordinance. (But) we wanted an exemption because our industry contracts are just not suitable for this," he said.

Vaughn said that the ordinance puts union contractors at a competitive disadvantage because they have to pay for benefits for all members, even those outside Dane County, while non-union contractors don't.

Domestic partner benefits are supposed to be negotiated into new union contracts once the old ones expire.

In the meantime, other county contractors worry about money. An official from one company who didn't want to be identified said that the mandate "could be a significant cost." The official said that it would "have to cover the cost" when bidding a contract."

The person said not bidding on country contracts at all "is a distinct possibility."