Spot iron ore vessel bookings to China in August by the world's two biggest exporters, Australia and Brazil, fell to a 9-month low, indicating strong demand from the world's top steel maker may be slowing as steel prices slump. Separate data showed on Tuesday that Brazil's iron ore exports, most of which goes to China, also dropped 8.4 percent to 23.3 million tonnes in August from their 2009 peak level in July, underscoring that China's iron ore buying spree may be losing some steam.