LONGMONT - UQM Technologies Inc. has extended its contract to supply Proterra Inc. with electric propulsion systems to power battery-electric buses.

Longmont-based UQM signed a three-year contract with Greenville, South Carolina-based Proterra. Terms of the deal were not disclosed.

"We have had a great business relationship with Proterra since the company was founded, supplying over $1 million of electric propulsion systems to them for their battery-electric buses," said Eric R. Ridenour, UQM Technologies' president and chief executive. "This new three-year agreement will build on that relationship, grow our volume with Proterra and provide an important customer for our newly introduced PowerPhase HD 220 product."

The new agreement expands the volume of systems that UQM will provide Proterra for its EcoRide BE35 battery-electric buses. Shipments to Proterra under the agreement are currently under way.