The law, approved by city legislators on Dec. 21, was published in Mexico City’s official register Tuesday and will take effect in March. It will allow same-sex couples to adopt children and municipal officials say it will make Mexico’s capital a “vanguard city” — and attract extra tourism revenues.

“Mexico City will become a center, where (gay) people from all over the world will be able to come and have their wedding, and then spend their honeymoon here,” said Alejandro Rojas, the city tourism secretary.

“We are already in talks with some travel agencies that are planning to offer package tours that include flights, hotels, guides, and everything they need for the wedding, like banquets,” said Rojas. “We are going to become a city on a par with Venice or San Francisco” — the current leader in the gay travel market segment.

The annual economic impact of lesbian, gay, bisexual and transgender travelers is about $70 billion in the United States alone, according to Community Marketing Inc., a tourism research company that specializes in gay and lesbian consumers.

Gay marriages of foreigners in Mexico City would presumably only be recognized by countries and states that also have legalized same-sex marriage. An exception is New York State, which doesn’t allow same-sex marriages but which recognizes those which were performed legally in other jurisdictions.

Mexico City’s law allows same-sex couples to adopt children, apply for bank loans together, inherit wealth and be included in the insurance policies of their spouse, rights they were denied under civil unions allowed in the city.

And of course,  even as Mexico City officials celebrated enactment of the law, others vowed to stop the marriages from taking place.