FACTBOX: Key facts about March auto sales

DETROIT (Reuters) - March auto sales fell 12 percent from a year earlier on an unadjusted basis, according to data from auto manufacturers on Tuesday. The following are highlights from the largest carmakers in the U.S. market.

Overall industry

* Total light vehicle sales -- 1.36 million units.

* First quarter sales -- 3.6 million units, down 8 percent.

General Motors Corp (GM.N: Quote, Profile, Research, Stock Buzz)

* Light vehicle sales down adjusted 12.7 percent (277,751 units), unadjusted sales down 19 percent

* Year-to-date sales down 9.7 percent

* Inventories at month-end: 874,000 units

* Cars/trucks: Car sales down adjusted 8 percent/light truck sales down 15.7 percent