BUENOS AIRES, Dec 30, 2010 (AFP) - A baby girl has become the first child of a legally married lesbian couple in Argentina, under a law approved by Congress that set a historic precedent for Latin America, officials said Thursday.

Bianca Juliana Gimenez Relea was registered with the surnames of both her birth mother - Paola - and Claudia, Paola's companion who witnessed the delivery.

On October 21, the pair became the third gay couple in northeastern Entre Rio province to get married since the law was passed July 15 amending the phrase "husband and wife" to "contracting parties" in Argentina's Civil Code.

It also extends equal rights to homosexual couples in matters of adoption, inheritance and social benefits.

The baby girl's ceremony was held at the Parana Civil Registry office and capped a seven-year relationship, media reported.

Paola was already pregnant when she married and said the girl was her first child, conceived with the help of a friend.