Truckload carrier Dart Transit Co. said it has assigned seven tractors powered by compressed natural gas to dedicated service for Andersen Window Corp.

General Electric Co. and Chesapeake Energy Corp. have signed a three-year agreement to accelerate the adoption of natural gas.

The use of liquefied natural gas as a U.S. truck fuel has a diverse array of proponents, including President Obama, ATA Chairman Dan England, corporations such as UPS Inc. and Ryder System and environmental activists. But as of now, the super-cold fuel is hard to find.

MOUNT HOLLY, N.C. — President Obama proposed a federal tax credit designed to encourage the trucking industry to move toward natural-gas and electric vehicles by helping underwrite their higher acquisition costs.

Engine maker Cummins Inc. said its 50-50 joint venture with Westport Innovations has introduced a 12-liter version of its natural gas engine.

Clean Energy Fuels Corp. said it has opened a new liquefied natural gas fueling station in Ohio.

Clean Energy Fuels Corp. on Monday said it has signed an agreement with tank truck carrier Green Energy Oilfield Services to build and supply a new liquefied natural gas fueling station in Texas.

LISLE, Ill. — Navistar Inc. and Clean Energy Fuels Corp. unveiled a joint offensive on Feb. 1 to expand the reach of natural-gas-powered vehicles in the heavy-duty trucking market.

LISLE, Ill. — Navistar Inc. and Clean Energy Fuels Corp. unveiled a program that will provide natural gas-powered trucks to customers at the same cost as diesel vehicles, if the customers commit to purchase their fuel from Clean Energy.