Gay couples have rushed to tie the knot in Argentina two weeks after the country became the first in Latin America to grant them the same marriage rights as heterosexual couples.

Talent agent Alejandro Vanelli, 61, wept as he exchanged vows with Ernesto Larrese, 60, an actor and his partner of 34 years.

"We never thought we'd get to this point," Mr Vanelli said after the service at a Buenos Aires registry office festooned with rainbow-coloured gay rights banners.

"It was time for our country to embrace equality after hundreds of years of restricting the rights of so many."

Guests threw rice over the newlyweds as they left the packed office, becoming the second couple to marry under the law signed by president Cristina Fernandez on July 21.

Another couple had exchanged vows hours earlier in a northern province and gay weddings are planned across the nominally Roman Catholic country.

The measure, which also lets same-sex couples adopt children, puts Argentina at the vanguard of gay rights in the region and underlines the Catholic Church's waning influence in Latin America.

Same-sex couples in Mexico City won the same rights as heterosexuals to marry and adopt children in December.

Uruguay allows same-sex couples to adopt but not to marry.

A few gay couples were married in Argentina prior to the law, but they had been granted marriage licences under one-off court rulings.

- Reuters