Brazil's Supreme Court has ruled that civil unions between same-sex couples must be allowed in this nation with more Roman Catholics than any other.

In a 10-0 vote, with one abstention, the justices decided Thursday that gay couples deserve the same legal rights as heterosexual pairs when it comes to alimony, retirement benefits of a partner who dies, and inheritances, among other issues.

The ruling, however, stopped short of legalizing gay marriage. In Latin America, that is legal only in neighbouring Argentina and in Mexico City.

Two men kiss during the 2009 Gay Pride Parade in Sao Paulo, Brazil. The parade is held annually to condemn homophobia and demand equal rights. Nelson Antoine/Associated PressSame-sex civil unions granting some rights to homosexual couples are legal in Uruguay and in some states of Mexico outside the capital. Colombia's constitutional court has granted same-sex couples inheritance rights and allowed them to add their partners to health insurance plans.

Brazil's ruling sets a judicial precedent that must be honoured by all public institutions, including notary publics where civil unions must be registered.

"This is a historic moment for all Brazilians, not just homosexuals. This judgment will change everything for us in society — and for the better," said Marcelo Cerqueira, who is with the gay rights group Grupo Gay da Bahia.

"Gays, lesbians and transsexuals will be recognized as being more human. We'll be more accepted by having our rights honoured."

The request for the Supreme Court to recognize civil unions came two years ago from the Brazilian attorney general's office, largely because legislation that would give same-sex couples the rights enjoyed by married heterosexual couples has been stalled in congress for more than a decade.

Brazil's constitution defines a "family entity" as "a stable union between a man and a woman." But the attorney general's office argued the clause is only a definition and not a limitation, and thus the charter does not say a stable union can "only" be between a man and a woman.

The attorney general also argued that the constitution does not specifically forbid a civil union between people of the same sex — and that failing to recognize same-sex unions violates the charter's defences of human dignity and equality.

A lawyer representing Brazil's National Conference of Brazilian Bishops, Jose Sarubbi de Oliveira, argued to the court that the constitution recognizes only a legal partnership between a man and a woman and that the justices would be wrongly interpreting the document to rule otherwise.

Oliveira said the document's lack of an explicit statement that a family partnership is limited to those between a man and a woman did not mean that "every type of union has to be considered."

'Gays, lesbians and transsexuals will be recognized as being more human. We'll be more accepted by having our rights honoured.'—Marcelo Cerqueira, gay rights activist

Ralph Lichota, a lawyer representing religious groups, told the court the legal recognition of same-sex couples should be left in the hands citizens.

"Power emanates from the people, and the Brazilian people are Christian," he said. "God created marriage when he created Adam and Eve. Just like the Brazilian people aren't ready to legalize marijuana, like they aren't prepared to have abortion, we're not ready for homosexual marriage."

Luis Roberto Barroso, a law professor at Rio de Janeiro State University, argued in a friend-of-the-court appearance before the justicies that allowing same-sex civil unions would mean "overcoming historical discrimination."

"The implications of a homosexual relationship are the same as those of a heterosexual one. To not recognize that is to say that the affection they [gays] have has less value and can be disrespected," said Barroso.

Grupo Gay da Bahia said in a recent report that 260 gays were murdered in 2010 in Brazil, up 113 per cent from five years ago.

"This ruling will help. The violence comes about because of impunity for those who commit it," said the group's Cerqueira.

"When a country judges a case like this in favour of us, it will have an impact across the judicial and law enforcement sectors."