The deal is worth around $1.14 billion, according to SR radio station.
Swedish Defense Minister Peter Hultqvist told the broadcaster that acquiring Patriots was in full compliance with the defense decisions taken by Swedish authorities in recent years, adding that the first deliveries are expected to take place in 2021.
"This system has been proven in action… there are a number of other countries that already have it and we expect the first delivery in 2021," Peter Hultqvist said.
Sweden has close relations with the North Atlantic Treaty Organization (NATO) and has been increasing its armed forces after decades of neglect. Earlier in 2017, Romania became the 14th nation to buy the missile delivery system, and this year Sweden and Poland joined the list. Sweden started talks over the purchase, initially worth around 10 billion crowns last November.
The Patriot is a long-range, all-altitude, air defense system capable of countering tactical ballistic missiles, cruise missiles, and advanced aircraft.