TransCanada Corp. has reached a deal to buy a gas-burning power plant in Pennsylvania for US$654 million from Talen Energy Corp., which is divesting some of its holdings to comply with regulatory requirements. Calgary-based TransCanada says the 778-megawatt Ironwood power plant in Lebanon, Penn., is a natural extension of its power business in the U.S. Northeast region, where the company now has over 4,500 megawatts of generating capacity.