Burger King Holdings Inc. agreed to be acquired by 3G Capital, a New York investment firm backed by Brazilian investors, for $3.3 billion in the biggest restaurant acquisition in at least a decade. The $24-a-share price is 46 percent more than Miami-based Burger King’s close Aug. 31, before reports of a deal surfaced. Under the terms of the agreement, the second-largest U.S. burger chain can solicit superior bids through Oct. 12, according to a statement today. The chain’s sales growth has slowed for two straight years as consumers ate out less during the U.S. economic slump. Burger King, which trails only McDonald’s Corp. in the U.S., has seen a slower recovery than its larger rival as its clientele suffered more from the recession, said Tom Forte, an analyst at New York- based Telsey Advisory Group. “Burger King’s heavy user -- young, male, and more likely to be a minority -- has had a higher rate of unemployment than the McDonald’s consumer,” Forte said in a telephone interview. The transaction with New York-based 3G amounts to about $4 billion including debt. The purchase would eclipse the 2007 sale of OSI Restaurant Partners Inc., the parent of Outback Steakhouse, as the biggest restaurant deal since Bloomberg started compiling data more than a decade ago.