U.S. retail sales declined in May because of a sharp drop in sales of automobiles.

Tuesday's report from the Commerce Department says U.S. auto sales slowed when Japan's multiple disasters hampered production of auto parts.

This is the first decline in retail sales in nearly a year. Experts watch retail sales because consumer demand drives most U.S. economic activity.

A separate measure of inflation at the wholesale level rose two-tenths of a percent. That is less than the gain in prior months because food prices declined and gasoline costs rose more slowly. This data is called the Producer Price Index and provides clues about future inflation at the consumer level.

On Wednesday, experts will publish the latest information on inflation. Economists surveyed by news organizations predict the study will show a modest increase in prices.