Ford has ended production of its compressed natural gas vehicles, the automaker announced in September. The company says it will focus on the development of other green technologies, such as hydrogen fuel cell vehicles.In the United States, Ford has been the leader in natural gas vehicles, having produced nearly 30,000 since 1997. Its models — including the Crown Victoria sedan, F-150 pickup and Econoline vans — are used by taxi companies, municipalities, police forces and utilities. Ford said that while the company's natural gas vehicles were profitable, they were not selling well enough to justify the program, according to a New York Times report. The company said that although it led the market in CNG the total volume compared to other products was minimal.In addition, Ford wanted to shift its engineers and resources to combined gas-electric vehicles like its new Escape Hybrid, to cleaner-burning gasoline technology like its very clean "partial zero emissions" Focus and to fuel-cell vehicles, the report said.