Chicago-based Hyatt Hotels Corp. has backed off plans to build a hotel at the World Expo Park in Orlando. Instead, Los Angeles-based Hilton Hotels Corp. will develop a 1,200-room Doubletree Hotel at the planned complex. Shortly after opening the Doubletree, Hilton will build another 1,200-room hotel with a Hilton flag at the park. Though financing for the World Expo Park project has yet to be obtained, the project is slated to open with the 1.2-million-square-foot World Expo Center, a 145,000-square-foot Osceola County Convention Center, 250,000 square feet of retail space and 100,000 square feet of office space.