(Updates with market context, Brazil data)
By Christine Murray
MEXICO CITY, Feb 10 (Reuters) - Mexico's America Movil said on Tuesday its fourth-quarter profit slumped 82 percent compared with a year earlier, as its exchange rate loss more than doubled after falling global oil prices hammered Latin American currencies.
The telecoms company, which is controlled by the family of billionaire Carlos Slim, said net profit in the October-December period fell to 3.083 billion pesos ($209 million) from 17.177 billion pesos in the same period a year earlier.
The net profit was less than a quarter of the 12.411 billion pesos analysts had expected in a Reuters poll.
Exchange rate losses more than doubled to 22.818 billion pesos in the quarter after Latin American currencies such as Brazil's real, Colombia's peso and Mexico's peso tumbled against the dollar.
Revenue rose 12.3 percent to 229.304 billion pesos, mostly driven by the inclusion of Telekom Austria in its results.
America Movil is in the midst of a regulatory crackdown in its home market, which continued to drag on its results, with Mexico wireless voice revenues plummeting 14.7 percent.
The company said in July it would sell assets to reach a market share of below 50 percent to avoid the new rules, though executives said in October they were not in a hurry and the sale would probably happen in 2015.
Despite the new rules designed to curb its dominance, it was able to add almost 1 million new wireless subscribers in Mexico.
AT&T Inc, a former Slim ally that has been seen as a front-runner to buy the assets, recently agreed to buy Mexico's No.3 and No.4 wireless operators Nextel and Iusacell. It has downplayed publicly its interest in buying from America Movil.
Latin America's biggest telecoms company has been hoping that growth in Brazil, which it says is now bigger than its Mexico business, can offset increased competition at home.
Growth in Brazilian pay TV, in which it is the market leader, drove a 5.6 percent rise in revenues in the country.
America Movil's shares closed down 0.12 percent at 16.16 pesos per share on Tuesday before the results were announced. ($1 = 14.7475 pesos at end 2014) (Reporting by Christine Murray; Editing by Simon Gardner and Lisa Shumaker)