FRANKFURT (Reuters) – RWE on Thursday said it has agreed to buy a 1.4 gigawatt gas-fired power plant from Vattenfall in a deal valuing the asset at 500 million euros ($534 million). The planned acquisition of Vattenfall’s Magnum plant, located in the Netherlands, is expected to close by the end of the third quarter, RWE said in a statement. ($1 = 0.9369 euros) (Reporting by Christoph Steitz; Editing by Riham Alkousaa)