* Growth in fuel demand decoupled with economic growth
* Distributors tripled infrastructure investment in two years
RIO DE JANEIRO Dec 11 (Reuters) - Gasoline consumption in Brazil will probably increase 12.2 percent in 2012 from a year earlier despite slower economic growth, testing national supply, fuel distributors association Sindicom said on Tuesday.
The increased demand largely did not result in fuel shortages, but it did cause delays in delivery to gas stations in some remote, but fast-developing parts of the country, Sindicom's President Alisio Vaz said.
"We have Chinese-level increases in gasoline sales that have decoupled from econonomic growth. It's been a big effort to keep the market supplied," he told journalists.
Total fuels sales -- including jet fuel, cooking gas and ethanol -- in the world's sixth largest economy, are rising 6.3 percent a year.
Brazil, once one of the region's fastest-growing economies, is expected to grow just 1 percent in 2012. Growth has stalled in part from lack of roads, trains and ports. Infrastructure has not kept up with increasing auto purchases.
Only the tiny northern state of Amapa recorded general fuel shortages this year, Vaz said, while some gas stations in other states in the remote Northeast were occasionally without fuel.
"We have bottlenecks in infrastructure that challenge gasoline and diesel delivery to the ports of the Northeast," he said. "Refineries are also at their limit in terms of production."
Vaz said fuel distributors increased investments in infrastructure and distribution to 1 billion reais ($481 million) in 2012 compared with 300 million reais in 2009 to meet the demand.
"We are talking about 20 percent growth in the demand for gasoline in the Northeast in 2012," he said. "It's hard to keep the country supplied with the same infrastructure we had 20 years ago," he said.
Other states where the demand for gasoline will grow more than 20 percent this year include agricultural powerhouse Mato Grosso, Piaui and Maranhao.
Diesel consumption will probably rise 6.8 percent in Latin America's largest economy, while hydrous ethanol consumption is expected to fall 10.4 percent. Hydrous ethanol fuels the country's flex-fuel car fleet that can also run on gasoline.
Gasoline in Brazil includes a 20 percent anhydrous ethanol blend, a requirement that stood at 25 percent until October 2011.