TRENTON, N.J. — With New Jersey's highest court opening the door to making the state the second in the nation to allow gay marriage, Utah activists on both sides of the issue offered differing opinions on its potential effects.

In a ruling Wednesday that fell short of what either side wanted or feared, the New Jersey Supreme Court declared 4-3 that homosexual couples are entitled to the same rights as heterosexual ones. The justices gave lawmakers 180 days to rewrite the laws.

The ruling is similar to the 1999 high-court ruling in Vermont that led the state to create civil unions, which confer all of the rights and benefits available to married couples under state law.

"Although we cannot find that a fundamental right to same-sex marriage exists in this state, the unequal dispensation of rights and benefits to committed same-sex partners can no longer be tolerated under our state Constitution," Justice Barry T. Albin wrote for the four-member majority.

The court said the state's Legislature "must either amend the marriage statutes to include same-sex couples or create a parallel statutory structure" that gives gays all the privileges and obligations married couples have.

The three dissenters argued that the majority did not go far enough. They demanded full marriage for gays.

In Utah, Bill Duncan, director of the Marriage Law Foundation, said the ruling re-affirms the need for the wording in Utah's constitutional amendment banning same-sex marriage that also bans other similar domestic unions.

"This decision makes it absolutely clear that those arguing that additional language is unecessary are clearly wrong," Duncan said. "It's now pretty obvious that courts are willing to order the (marriage) benefits, even if they're not willing to go all the way."

Mike Thompson, director of Equality Utah, disagreed, calling the New Jersey decision hopeful because it "properly recognizes there is no legal basis to discriminate against same-sex couples."

"There's no legitimate reason to discriminate against these families," he said. "It saddens me that in Utah families don't have the same types of protections that they do in New Jersey."

Gay rights activists had seen New Jersey as a promising place because it is a largely Democratic state in the Northeast. The only state to allow gay marriage is Massachusetts. The only states allowing civil unions are Vermont and Connecticut. New Jersey is also one of just five states that have no law or constitutional amendment expressly banning gay marriage.

If the court had legalized gay marriage outright, the effect could have been more far-reaching, and New Jersey could have become more of a magnet for gay couples than Massachusetts, which has a law barring out-of-state couples from marrying there if their marriages would not be recognized in their home states. New Jersey has no such law.