By Pratima Desai LONDON (Reuters) – The London Metal Exchange (LME) is studying Hong Kong as a location to expand its global metal warehouse network, five sources with knowledge of the matter said, hopeful success there might open the door to mainland China, its ultimate target. Registering warehouses in China, the world’s largest consumer of industrial metals, to store metal traded on the LME has been a strategic aim since Hong Kong Exchanges and Clearing (HKEx) bought the LME in 2012 for $2.2 billion. In a presentation made to the LME’s warehousing committee in December, seen by Reuters, the…