TEANECK, N.J. – Shortly after midnight, Steven Goldstein and Daniel Gross renewed their vows as New Jersey became the third state in the nation to offer civil unions for gay couples.

The law that took effect yesterday was “a big giant step forward,” said state Sen. Loretta Weinberg, a prime sponsor of the civil unions law, who hosted ceremonies in her office for couples including Goldstein and Gross.

The civil unions, which offer the legal benefits but not the title of marriage, were granted automatically to the hundreds of gay New Jersey couples who had previously been joined in civil unions or married in other states or nations.

For Goldstein and Gross, that meant reaffirming their Vermont civil union. They would have had the rights in New Jersey even without holding the midnight ceremony.

Their civil union license – No. 1 – was completed at 12:09 a.m. yesterday by Teaneck registrar Laura Turnbull.

Elsewhere across the state, a handful of town halls opened at 12:01 a.m. to accept license applications from couples who had not been joined previously.

They must wait 72 hours before they can hold civil union ceremonies – just like with weddings – and several planned to exchange vows early Thursday.

By midday yesterday, at least 16 couples registered for a civil union license.

Partners Thomas Mannix and Kevin Pilla, who have been together since 1983, arrived at Asbury Park City Hall at about 11:30 p.m. Sunday, so they could be among the first to fill out the one-page license application as soon as the clock struck 12:01 a.m.

“The things being granted are long overdue and very important to have, so we wanted to take advantage of it as soon as it was available,” said Mannix, a 44-year-old business analyst.

“But it was also bittersweet because it’s not full marriage. Once a separate class is made, a separate category, we get back to ‘separate but equal,’ which we’ve learned from the past doesn’t work.”

The American Civil Liberties Union joined in criticizing that aspect of the new law.

“If such a separate system of rights and an affixation of a different label were done on the basis of race, we would decry it, call it bigotry, see it as an affront to all New Jerseyans, and call it abhorrent and wrong,” said Ed Barocas, legal director for the group’s New Jersey chapter. “When it is done on the basis of sexual orientation, it is no less of an affront to all New Jerseyans, and no less abhorrent and wrong.”

Among the many new benefits under the civil unions law, gay couples gain the rights to adoption, child custody, visiting a hospitalized partner and making medical decisions. They also now have the right not to testify against a partner in state court.

However, the federal government and most states do not recognize the unions. That means, for instance, that a surviving member of a civil union would not be entitled to his deceased partner’s Social Security benefits. And if a partner is hospitalized in another state, the other may not have an automatic visitation right.

New Jersey lawmakers hastily created civil unions in December, less than two months after a state Supreme Court decision held that gay couples had a right to the same benefits as married couples.

Gay rights activists in the state say they’ll continue to press for full marriage rights through both political channels and lawsuits. Some social conservative groups, meanwhile, are pledging to block same-sex marriage by pressing for an amendment to the state constitution that prohibits such unions.

Forty-five states have legal or constitutional bans on same-sex marriages. Only Massachusetts allows gay couples to marry, while California offers domestic partnerships.