Israel is acquiring four advanced Sa'ar-class corvettes from Germany over the next five years under a $480 million deal signed on Monday.

The ships, which will be built by ThyssenKrupp Marine Systems but fitted with Israeli-made weapon systems, Israeli news reports said.

The deal was signed in Israel by Israeli Defense Minister Moshe Ya'alon and visiting German Defense Minister Ursula von der Leyen.

The ships will be used as part of a program to protect Israel's expanded Economic Exclusion Zone in the Eastern Mediterranean, where recent explorations discovered major oil and gas resources, Defense Update and The Times of Israel reported.

"This contract signed today is a significant event, representing a major increase in the defensive capability of the Israeli Navy, protecting offshore strategic sites located tens and hundreds of kilometers offshore" said Maj. General (ret) Dan Harel, Director General of the Israel Ministry of Defense.

As part of the arrangement, Germany is financing one-third of the cost for the corvettes. ThyssenKrupp will also purchase Israeli-made goods, invest in research and development and look into investing as much as $180 million in Israeli companies, Israeli officials were quoted as saying.