ZURICH, June 24 (Reuters) - Switzerland has started contract negotiations with manufacturers from France, Israel and South Korea for a second air defence system following delays to its order of U.S. Patriot missile systems, the government said on Wednesday. Switzerland in 2022 ordered Patriot missile defence systems made by Raytheon and Lockheed Martin for expected delivery by 2026-2028, but the timeline was pushed back four to five years due to the war in Ukraine.