"Our opinion should by no means be read to imply that the General Assembly may not grant and recognize for homosexual persons civil unions or the right to marry a person of the same sex," Judge Glenn T. Harrell Jr. wrote for the majority.

Plaintiffs said that the judges missed a historic opportunity to strike down a discriminatory law. Legislators on both sides of the debate predicted action on the issue in the next session. The heavily Democratic legislature has passed several gay-rights laws in recent years but has not voted on legalizing same-sex marriage or civil unions.

"I think history will hold them in contempt," plaintiff Lisa Polyak said of the judges. "To create a legal solution in a vacuum, that doesn't recognize that the constitution is there to support the people, is to create an ignorant and irrelevant solution."

State Sen. Richard Madaleno, who is openly gay, said he plans to introduce a bill to allow same-sex marriage. He also expects a proposal to create civil unions.

"I think we'll have a lengthy discussion next session about what the options are for legal recognition for gay people," Madaleno said.

Don Dwyer, one of the General Assembly's most conservative members, said he would introduce a constitutional amendment banning gay marriage as "insurance."

The ACLU of Maryland, which provided legal representation for the plaintiffs, said the fight to legalize same-sex marriage in Maryland would continue.

Many of the plaintiffs have children, and they argue that their families are being denied the stability and legal protection that comes from having married parents.

Lisa Kebreau, 39, and partner Mikki Mozelle, 31, who live in Riverdale, have three children — ages 20 months, 2 and 17.

"We really wanted them to understand how normal and good their family is — that their family is just like any other family," Kebreau said.

Nine same-sex couples and a gay man whose partner died filed the lawsuit in 2004 against court clerks who denied their applications for marriage licenses. Baltimore Circuit Judge M. Brooke Murdock in January struck down the law defining marriage as a union between one man and one woman, but the state immediately appealed.

Murdock's ruling was put on hold during the appeal and never took effect — unlike in Iowa, where same-sex marriage was legal for less than 24 hours last month. Massachusetts is the only state where gay marriage is legal, but nine other states have approved spousal rights in some form for same-sex couples — California, Connecticut, Hawaii, Maine, New Hampshire, New Jersey, Oregon, Vermont and Washington.

In throwing out the lawsuit, the Maryland Court of Appeals ruled that denying same-sex couples the right to marry does not discriminate based on gender because the state law applies equally to men and women. Maryland's Equal Rights Amendment, ratified in 1972, bans discrimination based on gender, but it was not intended to apply to sexual orientation, the court found.

The court also found that the state has an interest in promoting procreation and that the General Assembly "has not acted wholly unreasonably in granting recognition to the only relationship capable of bearing children traditionally within the marital unit."