Chrysler Group's December U.S. auto sales rose 10 percent, easily beating analysts' expectations, as the first of the major automakers to report sales on Thursday.

Chrysler showed its 33rd consecutive month of year-on-year sales gains, and its annual sales rose 21 percent.

Industrywide, U.S. auto sales for 2012 are expected to show a 13 percent rise to 14.5 million new vehicles, the best showing since 2007, driven by the slowly recovering economy, more available credit and the need to replace aging cars and trucks.

Polk, a research consulting firm, said it expects U.S. auto sales to hit 15.3 million in 2013, an increase of nearly 7 percent.

Each month, auto sales are an early indicator of consumer demand.

Chrysler is managed by its majority owner, Italian automaker Fiat SpA .

(Reporting by Bernie Woodall and Ben Klayman in Detroit; Editing by Maureen Bavdek)