A Lockheed Martin executive said today that finding consensus on a cost baseline with the Pentagon surrounding the next F-35 production contract has "proven more difficult than we expected." Officials from the company and the F-35 Joint Program Office are still working through negotiations surrounding a deal for the lots 15-17 aircraft, John Mollard, acting chief financial officer, told analysts during an earnings call -- an agreement that Lt. Gen. Eric Fick, F-35 program executive officer, previously told reporters he...