DETROIT – General Motors said it expects total sales of passenger cars in its Chevrolet brand to increase by 23 percent during the first half of 2011. The automaker said the total sales for Chevrolet will be up by 15 percent, due in part to the rise in passenger car sales.

General Motors said Chevrolet cars have outsold combined sales of trucks, crossovers and utilities in April, May, and June of this year. The company expects these sales to represent 47 percent of the brand’s sales for the first half of 2011. The last time cars led Chevrolet’s sales for three consecutive months was in May, June, and July of 1991. That year, cars represented 52 percent of Chevrolet sales, according to the automaker.

The automaker said it can attribute the Chevrolet brand’s growth in 2011 to the successful launch of the new Chevrolet Cruze and continued sales success of the Malibu. The company said both cars were among the top 10 best-selling vehicles in the industry in May, when the Cruze was also the best-selling compact car in the United States. GM expects the Malibu’s total sales to show an increase of 17 percent during the first six months of 2011.

General Motors stated that another factor influencing growth in the sales of passenger cars is the use of improved four-cylinder engines in its vehicles. The company estimates that 46 percent of Chevrolet buyers chose a four-cylinder model during the first half of 2011, which is double the percentage of four-cylinder vehicles consumers purchased five years ago.