Audi AG has raised its worldwide sales forecast for 2011 to 1.3 million vehicles, up 100,000 units, because of brisk sales in the first eight months, said Peter Schwarzenbauer, board member for sales and marketing.Audi sold 1.1 million vehicles worldwide last year and originally forecast 2011 sales of 1.2 million units, Schwarzenbauer said.Audi\'s higher-than-expected volume means the brand will hit annual sales of 1.5 million vehicles worldwide sooner than 2015, its initial target, Schwarzenbauer said.Audi is on track to pass Mercedes-Benz this year as the second-best-selling premium brand worldwide. BMW has held the sales crown since 2005, when it topped Mercedes-Benz.U.S. sales at Audi are expected to rise 10 percent in 2011 from 2010, when the brand sold 101,629 vehicles, Schwarzenbauer said. Audi sold 75,256 vehicles in the United States during the first eight months of 2011.That\'s up 15 percent from the same period in 2010 and slightly above the 11 percent increase in total U.S. light-vehicle sales in the period.Most of the growth in the United States has been fueled by demand for Audi\'s larger cars, such as the redesigned A8, the all-new A7 and the A6, which accounted for 26 percent of Audi\'s sales, up from 13 percent in 2008, Schwarzenbauer said.Schwarzenbauer said China will become Audi\'s biggest market in 2011, overtaking Germany.At the beginning of the year, Audi predicted China sales of 280,000 vehicles in 2011 but now expects to sell more than 300,000 units, he said.The automaker\'s biggest seller in China is a long-wheelbase version of the A6 sedan.