AUTOS

Ford to Begin Sales of Natural Gas Trucks: The auto maker announced Friday, at the Eco Expo in Los Angeles, that it will begin this fall offering, with full warranties, natural-gas versions of its F-Series pickup truck. The trucks will be modified by outside companies to use the alternative fuel, as well as gasoline. Ford said last week that conversion to natural gas could add $3,000 to $5,000 to the regular price of a vehicle though the exact cost will be set by the companies that do the work. The company has not yet determined how many of its 500 California dealers will sell and service the trucks.