Chrysler Group LLC reported a 34 percent increase in March auto sales, the first major automaker to report sales for a month expected to show signs of a robust recovery for the U.S. auto industry.

It was the 24th consecutive month that the No. 3 U.S. automaker showed a year-on-year sales gain.

Other major automakers will report March sales later on Tuesday, and most expect significant sales gains.

Analysts surveyed by Thomson Reuters expect an annualized sales rate for March of 14.74 million vehicles, which would be a rise from last March's 13.1 million sales rate. Analysts say pent-up demand, easier credit, more fuel-efficient product offerings and mild weather helped boost March sales.

Ford Motor Co will show a 5 percent sales gain over March 2010 and will show the best new-vehicle U.S. sales in five years, Mark Fields, Ford Americas president, said on CNBC. This met sales expectations from auto consultant Edmunds.com.

General Motors Co is expected to show a rise in March sales of more than 20 percent over a weak March 2011, and Toyota Motor Corp <7203.T> sales are expected to rise as much as 22 percent, Edmunds said.

Mike Jackson, chief executive of the largest auto retailer, AutoNation Corp , also said on CNBC the company raised its 2012 sales forecast to about 14.5 million from 14 million, based on the strongest quarter for auto sales since before the sales downturn that began in late 2008.

(Reporting By Bernie Woodall; Editing by Maureen Bavdek)