By Julia Payne and Marwa Rashad LONDON (Reuters) – Top U.S. gas exporter, Freeport LNG, has retracted the force majeure it initially declared after an explosion in June, a development that could cost its buyers billions of dollars in losses, a document showed and three trading sources said. Force majeure is a notice used to describe events outside a company’s control, such as a natural disaster, which usually releases it from contractual obligation without penalty. The force majeure would also have allowed Freeport’s LNG buyers to exit their own agreements to deliver gas to end users. Instead,…