Prices at the wholesale level rose at the fastest pace in nearly 3 years in May, pushed higher by a sharp jump in the cost of gasoline and a record increase in the price eggs related to an outbreak of avian influenza. But outside of increases in volatile food and energy costs, core inflation remained moderate.

The Labor Department says its producer price index spiked 0.5 percent in May, the biggest one-month increase since September 2012. The increase followed a 0.4 percent drop in wholesale prices in April. The May increase reflected a 17 percent rise in gasoline prices, the biggest hike since August 2009, and a record 56.4 percent surge in egg prices.

Core prices, which exclude energy and food, rose just 0.1 percent in May.