Nov. 13 (Bloomberg) -- America Movil SAB, Latin America's largest mobile-phone company, will begin offering high-speed wireless Internet in Brazil tomorrow after a government ruling allowed companies to use existing frequencies to offer the service.

The company will sell the service to 33 million customers in six cities in Brazil, Mexico City-based America Movil announced today in Sao Paulo. Service will begin tomorrow in Brasilia, Recife and Fortaleza. It will be available in Porto Alegre next week and in Sao Paulo and Rio de Janeiro next month.

Controlled by billionaire Carlos Slim, America Movil is the second company to begin offering so-called third-generation wireless this month in Brazil. Telemig Celular SA, controlled by Sao Paulo-based Vivo Participacoes SA, introduced its version last week.

Telemig and America Movil, which sells services under the Claro brand, are seeking to boost holiday sales with the new service, using frequencies that were acquired for old mobile- phone technology. Brazil's telecommunications regulator, Anatel, plans to auction new third-generation licenses in December.

America Movil shares rose 2.04 pesos, or 6.7 percent, to 32.62 pesos in Mexico City. The stock has climbed 34 percent this year, compared with an 11 percent gain in the Mexico Bolsa index.

Faster Connections

The company's wireless connections will be faster than those available to most of the 6 million Brazilians with broadband Internet access, Joao Cox, president of America Movil's Brazilian unit, told reporters today.

Claro will charge 76.90 reais ($43.56) to 323.90 reais a month for the service. Cox said the company also plans to offer it through prepaid phones. The company will be able to expand the service after it buys new frequencies at the auction, he said.

Claro, Brazil's third-biggest mobile-phone provider, has been taking market share from Vivo, the biggest, according to Anatel. Claro added a record 1.7 million customers in Brazil in the third quarter. Its market share has risen to 24.8 percent since February, while Vivo's has fallen to 28.1 percent.

TIM Participacoes SA, owned by Milan-based Telecom Italia SpA, is Brazil's No. 2 wireless carrier with 25.7 percent of the market. Madrid-based Telefonica SA and Lisbon's Portugal Telecom SGPS share control of Vivo.

America Movil has said it plans to begin offering third- generation services in Mexico in the first quarter of 2008.

To contact the reporter on this story: Romina Nicaretta in Sao Paulo at rnicaretta@bloomberg.net

Last Updated: November 13, 2007 16:41 EST