The Swiss executive branch has announced a proposal to purchase three dozen advanced fighter jets from U.S. manufacturer Lockheed Martin, which beat three rivals to land a contract worth more than 15.5 billion Swiss francs ($16.75 billion) over three decades.

The Federal Council, the Swiss seven-member executive, decided Wednesday it will advise parliament to buy 36 F-35A fighters from Lockheed Martin, as well as five Patriot ground-based air-defense system units from U.S. contractor Raytheon, for another 3.6 billion francs, over 30 years.

The purchases are part of a multi-year fleet refurbishment by the Swiss air force called “Air2030” because the division's current equipment will reach the end of its service life by 2030, the defense department said in a statement.

Other contenders for the fighter-jet contract along with Lockheed Martin and Boeing’s F/A-18 Super Hornet were France’s Rafale -- produced by Dassault Aviation -- and the Eurofighter from an Airbus-led consortium.

The decision was made after a “comprehensive technical evaluation” based on a cost-benefit analysis, the department said, adding the total F-35A costs including procurement and operating costs came in 2 billion francs less than the second-lowest bidder.