UPS says it has placed the largest-ever order for commercial hybrid electric vehicles as it seeks to boost its use of alternative-fueled trucks.

The Sandy Springs-based delivery giant said Tuesday that it ordered 200 of the HEVs, along with an additional 300 vehicles powered by compressed natural gas.

The orders will expand its alternative-fuel fleet by 30 percent, to 2,218 vehicles from 1,718, UPS said.

UPS expects to deploy the 200 HEVs in 2009. It already uses 50.

The 200 trucks are expected to save 176,000 gallons of fuel annually as well as reduce emissions, UPS said.

The UPS HEV and CNG vehicles are indistinguishable from its conventionally powered brown delivery trucks.

Chassis for the HEV and CNG trucks will be bought from Freightliner Custom Chassis Corp., with Eaton Corp. supplying the hybrid power system for the HEVs, UPS said.