According to a Reuters story (excerpts only):
The Pentagon has reached an agreement with Lockheed Martin Corp on a $450 million program to enhance electronic warfare equipment on the F-35 fighter jet, and integrate Israeli-unique systems beginning in 2016, according to sources familiar with the negotiations.
The deal, to be finalized in coming weeks, marks a big step forward for Israel’s $2.75 billion agreement to buy 19 F-35 jets, which was signed in October 2010 and includes options for up to 75 of the radar-evading fighters.
The Pentagon said the Israeli foreign arms sale could be worth up to $15.2 billion if all options are exercised, when it first approved the sale in September 2008.
“This agreement kicks off the Israeli program,” said one of the sources, who was not authorized to speak on the record. “Now all of the agreements are in place.”
The F-35 will allow for even greater collaboration in the coming years with Israel, a critical strategic ally for the United States at a time when much of the Middle East is in turmoil….