Washington - A rise in food and gas costs drove a measure of wholesale prices up sharply in May. But outside those volatile categories, inflation was mild.

The Labor Department said Friday that the producer price index rose 0.5 percent in May from April. Gas prices rose 1.5 percent last month, and food costs increased 0.6 percent.

The increase last month followed a 0.7 percent decline in April and a 0.6 percent drop in March, both of which were driven by steep declines in gas prices.

Core prices, which exclude food and energy, rose just 0.1 percent in May. That matches the April increase.

The index measures price changes before they reach the consumer.

Source: Associated Press