(Adds details from news conference, byline)
By Andrea Shalal
WASHINGTON, June 12 (Reuters) - Lockheed Martin Corp's F-35 fighter jet is making steady progress but needs further work to accelerate software development, increase reliability and lower the cost of operating and maintaining the new warplanes, the Pentagon's chief weapons buyer said on Thursday.
Frank Kendall, undersecretary of defense for acquisition, technology and logistics, told reporters the Pentagon was looking at a series of measures, including incentives tied to future payments and investments in process improvements, to cut the cost of building, operating and maintaining the planes.
Air Force Lieutenant General Chris Bogdan said the program had already lowered the projected cost to fly, operate and repair the jets by 9 percent, and hoped to eventually achieve a 30 percent reduction from an initial estimate that put the "sustainment" cost at $1.11 trillion over the next five decades.
Kendall, Bogdan and other U.S. officials spoke with reporters after a two-day meeting of top officials with the key companies and countries involved in the $398.6 billion program, the Pentagon's costliest weapons program.
Kendall said the Pentagon was also starting to look at a possible multi-year procurement agreement, given the large numbers of jets to be bought by the U.S. military and other countries, which could help further lower the acquisition cost.
Lockheed is developing three models of the F-35 for the U.S. military and eight countries that helped fund its development: Britain, Australia, Canada, Turkey, the Netherlands, Italy, Norway and Denmark. Israel, Japan and South Korea have also announced plans to buy the new warplane.
Kendall said the Marine Corps, Air Force and Navy were still on track to meet the target dates they have set in 2015 through 2018 for being able to use the jets in combat.
But he said the Block 3F software needed for the Navy's F-35 C-model, which will operate from an aircraft carrier, was about six months behind schedule due to the challenges involved in integrating data from a wide range of sources, including other airplanes, and being able to test the software.
Bogdan said the program office was working as hard as it could to avert or shorten any delay in the 3F software, but said a delay in the software would not necessarily force the Navy to postpone its plan to start using the jets in combat from 2018.
The Navy is slated to start testing its C-model jets on an aircraft carrier this fall for the first time.
The officials said the government was working with Lockheed and engine maker Pratt & Whitney, a unit of United Technologies Corp, to identify tens of millions of dollars in investments in process improvements, design changes and other measure to lower the cost of building and operating the jets.
Kendall said the investments would be carefully reviewed to ensure companies were able to recover their investments and that the measures would truly lower costs. He said Lockheed and Pratt also needed to work more closely with suppliers to cost cuts. (Reporting by Andrea Shalal; Editing by Bernard Orr)