GM may cut Volt output if sales falter: exec DETROIT (Reuters) - General Motors Co will cut production of its Chevrolet Volt if sales of the plug-in hybrid fall short of estimates in the first half of the year, GM vice chairman Steve Girsky said on Tuesday. "It's about matching supply and demand," Girsky said at an auto industry event. "I think it will be May or June before we really know if this thing has legs," he added. We are prepared for it if it does. Girsky declined to offer a sales forecast for the Volt in 2012. Last year, sales of the plug-in hybrid fell short of GM's expectations. The largest U.S. automaker sold about 8,000 Volts last year, a little more than half of its annual target. Slow sales of the Volt would hardly make a dent in GM's overall U.S. sales, which rose 13 percent to 2.5 million last year. Even so, the Volt has become a symbol of GM's effort to transform itself with a focus on fuel-efficiency after the automaker emerged from a U.S.-funded bankruptcy in 2009. Reporting by Deepa Seetharaman; Editing by Matt Driskill