After their first attempt to wed earlier this month in Buenos Aires was thwarted, gay rights activists Jose Maria Di Bello and Alex Freyre took their civil ceremony to the capital of Argentina’s Tierra del Fuego province, where a sympathetic governor backed their bid to make Latin American history.

The couple exchanged rings Monday in Ushuaia, the southernmost city in the world, closer to Antarctica than Buenos Aires. The informal ceremony was witnessed by state and federal officials.

“My knees didn’t stop shaking,” said Di Bello. “We are the first gay couple in Latin America to marry.”

Di Bello, 41, an executive at the Argentine Red Cross, met Freyre, 39, executive director of the Buenos Aires AIDS Foundation, at an HIV awareness conference. Both are HIV-positive. At the indoor civil ceremony, the grooms wore sport coats without ties, and had large red ribbons draped around their necks in solidarity with other people living with HIV.

Argentina’s Constitution is silent on whether marriage must be between a man and a woman, effectively leaving the matter to provincial and city officials. The men tried to get married in Argentina’s capital but city officials, who had earlier said the ceremony could proceed, refused to wed them citing conflicting judicial rulings.

Di Bello said Ushuaia initially declined to authorize the marriage, but went ahead after the couple received backing from Tierra del Fuego province. Gov. Fabiana Rios said in a statement that gay marriage “is an important advance in human rights and social inclusion and we are very happy that this has happened in our state.” An official representing the federal government’s antidiscrimination agency, Claudio Morgado, attended the wedding and called the occasion “historic.”

Many in Argentina and throughout Latin America remain opposed to gay marriage, particularly the Roman Catholic Church.

“The decision took me by surprise and I’m concerned,” Bishop Juan Carlos, of the southern city of Rio Gallegos, told the Argentine news agency DyN. He called the marriage “an attack against the survival of the human species.”

But same-sex civil unions have been legalized in Uruguay, Buenos Aires, Mexico City and some states in Mexico and Brazil. Marriage generally carries more exclusive rights such as adopting children, inheriting wealth and enabling a partner to gain citizenship. Legal analyst Andres Gil Dominguez said the Tierra del Fuego government appeared to base its authorization on a broad interpretation of the Argentine Constitution and obligations under international treaties.

Rios said her province’s approval was based on a ruling by a Buenos Aires judge who declared two provisions of the constitution discriminatory and gave the go-ahead for the Dec. 1 marriage, which was then blocked by another judge’s ruling based on civil law.

Individual provinces may not have final say over same-sex marriages for long. A bill that would legalize gay marriage was introduced in Argentina’s Congress in October but it has stalled without a vote. Argentina’s Supreme Court currently is analyzing appeals by same-sex couples whose marriages were rejected. A Supreme Court justice said on Monday that the high court would likely rule on issues of same-sex marriage sometime in 2010, but could defer to Congress if legislation moves forward.

Only seven countries in the world allow gay marriages: Canada, Spain, South Africa, Sweden, Norway, the Netherlands and Belgium. U.S. states that permit same-sex marriage are Iowa, Massachusetts, Vermont, Connecticut and New Hampshire. Earlier this month, lawmakers in Mexico City made it the first in Latin America to legalize same-sex marriage. Leftist Mayor Marcelo Ebrard was widely expected to sign the measure into law.

With the law awaiting President Tabare Vazquez’s signature, gay rights groups have been celebrating the prospect that Uruguay could become the first country in Latin America to give gay and lesbian couples the opportunity to adopt.

But nowhere in the law does it specifically say that homosexual couples have a right to adopt. And in some places, it suggests otherwise — for example by specifying how the child should take a mother and father’s surnames.

Lawyers, judges and even the law’s own authors now have doubts about how the law will be applied.

Under Vazquez, Uruguay already legalized gay civil unions and ended a ban on homosexuals in the military, despite strong disapproval from the Roman Catholic Church.

The church also campaigned against the adoptions law, which shifts much of the decision-making to the national Institute of Children and Adolescents, and away from a system in which individual lawyers, notaries and religious groups had a central role.

The new law would drop a requirement that children can only be adopted by legally married couples or single parents.

Deputy Margarita Percovich, who wrote the law, acknowledged that it doesn’t directly mention same-sex adoptions, but said it would enable them because gays and lesbians already can legally form civil unions, and “the law enables couples in civil unions to adopt children without impediment.”

But Attorney Juan A. Ramirez, an expert in civil rights law, told the leading newspaper El Pais that judges still won’t be able to approve same-sex adoptions, because this intent isn’t explicitly described in the law.

“Any objective interpretation of the law would conclude that either they forgot to mention that gay couples can adopt, or they didn’t want to mention it. They didn’t want to take the bull by the horns and resolve it clearly — they left it undefined,” he said.

Family judge Estrella Perez said the judges association now plans to meet “to see how to resolve these doubts.”

“We all have them.”

And a lawyer for the institute, Edgard Marzarini, told reporters that he doesn’t know how to resolve a same-sex adoption given the law’s requirement that a child take a mother and father’s surnames: “These are the holes that later give us problems.”

The Senate’s final approval Wednesday makes Uruguay the first country in Latin America to allow gay and lesbian couples the opportunity to adopt.

The executive branch now will decide when the law takes effect. The change is supported by socialist President Tabare Vazquez’s Broad Front coalition, while the Roman Catholic Church has voiced strong disapproval.

Under Vazquez, Uruguay already legalized gay civil unions and ended a ban on homosexuals in the military.

The law gives judges less say over adoptions and shifts decision making to the national Institute of the Children and Adolescents.

Despite opposition from Uruguay’s Roman Catholic Church and some of the political opposition, the 99-seat Chamber or Representatives on Thursday passed the bill 40-13, with the remaining members absent.

It goes next to the Senate, which approved an earlier version of the bill in July but must now vote again on modifications.

If it becomes law, Uruguay would be the first country in Latin American to allow adoption by gay and lesbian couples.

The law supported by socialist President Tabare Vazquez’s Broad Front coalition, which has already legalized gay civil unions and ended a ban on homosexuals in the armed forces.