Ford is developing a lightweight, more fuel-efficient pickup truck to slot in below its flagship F-150.

The new pickup truck, code-named P525, is being engineered on the F-150's platform. But it will be lighter and slightly smaller, supplier and industry sources told Automotive News. The pickup is scheduled to go into production during the first half of 2011 at Ford's Michigan Truck Plant in Wayne, Mich., sources said.

Ford may call the truck the F-100, bringing back a nameplate used for decades beginning in the 1950s. The new truck is larger than the Ford Ranger. But it might help take the place of that compact pickup, which could go out of production in 2009 when Ford's Twin Cities plant in St. Paul., Minn., closes. Ford hasn't said whether the Ranger will continue.

The new pickup is in Ford's cycle plan, sources said. But it has not received final approval.

Mark Fields, Ford president of the Americas, would not confirm plans for a slimmed-down truck in a recent interview. But he did acknowledge that Ford must take weight out of its pickup trucks to meet new fuel-economy standards.

"When you see what the F series makes up in terms of the composition of our vehicle lineup, clearly that's one area we really have to focus on," Fields said.

The new pickup truck will have unique sheet metal and innovative storage space, sources said. It could be powered by a version of Ford's new V-6 EcoBoost engine, which uses turbocharging and gasoline direct injection.