NEW YORK (AP) – An appeals court is weighing whether New York should recognize a gay civil union from Vermont and allow a Long Island man to sue a Manhattan hospital for malpractice in the death of his longtime partner.

The court will decide to uphold or overturn a Long Island judge’s ruling that John Langan could sue St. Vincent’s Hospital for allegedly mishandling the case of his partner, Neal Conrad Spicehandler, who died at the hospital after he was hit by a car in midtown Manhattan.

The case turns on whether Langan and Spicehandler’s 2000 civil union in Vermont made Langan a spouse with the right to sue the hospital under New York law.

Nassau County Supreme Court Justice John Dunne ruled in Langan’s favor last year, but the hospital appealed.

Some gay rights advocates said they believe a victory for Langan could lay the foundation for New York to recognize same-sex marriages from Massachusetts and countries such as Canada and Belgium.

Some experts said, however, that a victory for Langan could have more limited implications.

“This is an important step, but it doesn’t usher in gay marriage in New York state,” said Katherine Franke, an expert in gay rights and constitutional law at Columbia University School of Law.

A lawyer for St. Vincent’s told the appeals court that Dunne had overstepped his authority and contradicted the state Legislature’s decisions not to recognize gay and lesbian partners as spouses.

“Judges can’t change law where the Legislature has spoken,” attorney Paul Blutman said.

New York Attorney General Eliot Spitzer and a group of five New York bar associations have filed briefs supporting Lambda Legal, the gay rights law center representing Langan.

Lambda argued that New York had long recognized relationships such as common-law marriages that were created in other states but would not have been permitted in New York.

New York’s highest court even ruled in 1953 that the state had to recognize a Rhode Island marriage between a man and his niece, Lambda attorney Adam Aronson said.

“New York has a long history of respecting a legal spouse status that was created somewhere else, even if New York wouldn’t allow that spouse to be created here,” Aronson said.

St. Vincent’s spokesman Michael Fagan declined to comment on the specifics of the case, saying only, “In New York state, the law is that unless you’re married you’re not entitled to spousal benefits. We’re not looking to expand the law or restrict the law.”