ALBANY – The retirement plan for state and municipal workers will treat same-sex couples who wed in Canada as legally married, Comptroller Alan Hevesi said yesterday.

Mr. Hevesi, the elected official who administers the plan, confirmed his decision after a gay rights group, the Empire State Pride Agenda, publicized the comptroller’s recent correspondence with a state employee who is considering a Canadian marriage.

The retirement system “will recognize a same-sex Canadian marriage in the same manner as an opposite-sex New York marriage,” Mr. Hevesi wrote last week to the employee of the Insurance Department, Mark Daigneault.

Officials at the Pride Agenda hailed the ruling as the first time that a New York State agency has officially declared that it will recognize gay and lesbian marriages.

Similar policies were previously adopted in New York by municipalities, such as the cities of Buffalo and Rochester, and insurance companies, such as Allstate, Geico, and State Farm, according to the director of public policy and government affairs at the Pride Agenda, Ross Levi.

“Today’s important development is that finally a state actor has said that your marriage is just that – a marriage,” Mr. Levi said.

“As a dad with two sons, I want to make sure I’m doing everything I can to protect my family,” said Mr. Daigneault, who lives in the Albany area. “I thought if I sent this letter to the comptroller about retirement benefits, I could insure I was doing a good job as a dad.”

Mr. Daigneault said he and his partner consider themselves married already, having held a commitment ceremony 10 years ago. He said they wanted to be sure a Canadian marriage license would make a real difference in their lives before taking the trouble to obtain one.

Mr. Hevesi’s letter cited New York’s historic adherence to the legal principle of “comity,” under which a state automatically recognizes marriages from other jurisdictions even if they could not legally be performed within its own borders. Officials said the opinion does not necessarily apply to civil unions and marriages in other states, where the legal issues are slightly different.

A legal expert opposed to gay marriage, Mathew Staver of Liberty Counsel, disputed Mr. Hevesi’s interpretation of the law.

“That is a back-door approach to legalizing same-sex marriage which I don’t believe is permissible in New York through the front door or the back door,” said Mr. Staver, whose group, based in Orlando, Fla., has filed dozens of lawsuits against gay marriages in New York and other states.

He said states traditionally use comity to overlook technical variations in marriage laws – such as the age of consent – and not to change the definition of marriage itself.

“The question is whether you really even have a marriage to begin with,” Mr. Staver said. “The basic premise in New York is, and always has been, that marriage is for opposite-sex couples.”

Mr. Hevesi’s letter, however, cites an opinion issued by Attorney General Eliot Spitzer in March 2004, shortly after the mayor of New Paltz began marrying gay and lesbian couples. Mr. Spitzer declared that New York law does not permit officials to marry same-sex couples, but does recognize legally sanctioned marriages from other states and countries.

“New York law presumptively requires that parties to such unions must be treated as spouses for the purposes of New York law,” the opinion from the attorney general said. “The only exceptions to this rule occur where recognition has been expressly prohibited by statute, or the union is abhorrent to New York’s public policy.”

The opinion went on to say that this “abhorrence” rule has been interpreted narrowly to cover situations such as polygamy and incest. Meanwhile, state government and many local governments in New York offer employment benefits to domestic partners of the same sex, suggesting that such relationships are not abhorrent to state policy.

A sponsor of legislation to legalize same-sex marriage in New York, Assemblyman Richard Gottfried of Manhattan, called the decision “100% correct on the law and on the merits.”

“Hevesi’s ruling will help move us toward the day when same-sex couples do not have to go out of state to have their humanity fully recognized,” Mr. Gottfried said in a statement.

A spokesman for the state Catholic Conference, Dennis Poust, said the state’s Roman Catholic bishops are worried Mr. Hevesi’s decision “will be one more piece of evidence to bolster the legal case for anyone bringing suit to challenge the state’s marriage laws.”

“This could help pave the way for same-sex marriage in New York state,” Mr. Poust told the Associated Press yesterday.

With 315,000 beneficiaries and 614,000 working participants, the New York State and Local Retirement System covers employees of state government and most municipalities. Public school teachers and New York City workers have separate retirement systems.

The New York City comptroller’s office, which administers the city retirement systems, has not issued a similar opinion on same-sex marriages, a spokeswoman said yesterday.

Under Mr. Hevesi’s decision, which is legally binding, gay and lesbian couples who marry in Canada are entitled to certain benefits not available to unmarried domestic partners. The surviving spouse of an employee, for example, is entitled to annual cost-of-living adjustments in benefit payments, while other beneficiaries are not.

Mr. Hevesi said his office had simply interpreted the law in response to a request from a plan member, something it does hundreds of times a year.

“In that sense the process was routine,” he said. “Obviously the substance was not routine. I didn’t go out looking for an instance where we could make a statement.”