U.S.-based automakers say their sales rose sharply in 2011 as consumers gained confidence, interest rates stayed low, and consumers replaced aging vehicles they held onto during the recession.

General Motors says its sales rose 13 percent, as customers bought 2.5 million of its vehicles.

Rival Ford posted an 11 percent gain, and sold just over two million cars and trucks.

Chrysler says its U.S. auto sales rose a sharp 26 percent, as customers bought 1.4 million of its vehicles in 2011. The company's iconic Jeep brand boosted Chrysler's figures.

The 2011 sales increases are a major improvement over 2009, when sales hit a 30-year low during the worst recession in decades. Washington used emergency loans to bail out Chrysler and rival General Motors.

The financial crisis prompted U.S. auto companies to severely cut costs, streamline production, and introduce new, more fuel-efficient vehicles.

A study earlier this week said global auto sales will grow nearly 7 percent in 2012, helped by strong gains in China and some other emerging markets. The study says world wide auto sales will probably hit 77.7 million vehicles this year.