A law which recognizes the unions of gay and lesbian couples takes effect Thursday in Chile.

Chile's civil union law applies to opposite-sex and same-sex couples.

The legislation, first introduced in 2011 by former President Sebastian Pinera, allows couples living together to enter a legal contract. As many as 2 people could benefit from the law.

Co-habiting couples who register their unions will be able to claim pension benefits and inherit property if their partner dies. Registering will also make it easier to get custody of a partner's child in the event he or she dies.

According to the BBC, 1,600 couples have expressed interest in registering their unions.

Several lawmakers have backed legislation which would make Chile only the fourth South American country behind Brazil, Argentina and Uruguay to allow gay couples to marry. Gay couples can also marry in several states in Mexico, plus the federal district of Mexico City.