WASHINGTON — Lockheed Martin won an additional $18.5 million to continue work on developing an F-35 upgrade program, the Defense Department announced this week.

The Pentagon awarded Lockheed a $18.5 million modification to a previously awarded cost-plus, fixed-fee contract for development efforts for the F-35 Block 4 modernization program, according to a March 28 announcement.

The work, which is is expected to be complete in May 2017, will be performed in Fort Worth, Texas, where Lockheed builds the jets.

The contract includes $7.4 million, or 40 percent of the total, for the Air Force's F-35As; $3.7 million, or 19.5 percent, for the Navy's F-35Cs; $3.7 million, or $19.5 percent, for the Marine Corps F-35Bs; and $3.7 million, or 21 percent, for the international partners.

Although Lockheed's work will apply to all F-35 variants, the contracting authority is Naval Air Systems Command in Patuxent River, Maryland.

The Block 4 modernization program is expected to cost $3 billion over the next six years. The effort will include upgrades to maintain viability against evolving threats, as well as a switch to a so-called open systems architecture that would make it easier to swap out sensors and other equipment on the jets in the future.

Lt. Gen. Christopher Bogdan, chief of the F-35 joint program office, said earlier this month he expects a contract award for Block 4 in late 2018. He also said the Pentagon's Joint Requirements Oversight Council will likely approve a road map for Block 4 this summer.

Email: lseligman@defensenews.com

Twitter: @laraseligman

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