NEW Zealand's Parliament has voted in favour of allowing same-sex marriage.

Two-thirds of Parliament backed a move to amend the current marriage act to allow same-sex couples to marry, making New Zealand the first country in the Asia-Pacific region to do so.

Louisa Wall, the openly gay opposition Labour Party MP who promoted the bill, said: "It shows we are building on our human rights as a country."

The bill was widely expected to pass, given similar support for the change in a preliminary vote last month. It is expected to come into effect in August.

New Zealand becomes the 13th country to legalise same-sex marriages, after Uruguay passed its own law last week. Australia last year rejected a similar proposal.

The bill was opposed by the Roman Catholic Church and some conservative religious, political and social groups that claimed it would undermine the institution of the family.

The law makes it clear clergy can decline to preside in gay marriages if they conflict with their beliefs.

The law to allow same-sex marriages comes after New Zealand gave same-sex relationships partial legal recognition in 2005 with the establishment of civil unions.

"I have a boyfriend, so it means we can get married," said Timothy Atkins, a student who was listening to the hearing. "It's important to be seen as equal under the law."