Flush with petrodollars and ambitious plans, Nigerias banks are coming to London. Guaranty Trust Bank, one of Nigerias leading banks, has just been authorized by the UKs Financial Services Authority to operate as a bank in the UK. Its subsidiary, GTB UK, which is based in Margaret Street in London, will focus on commercial activity in areas where there are already established links between Nigeria and the UK and the other countries where it operates, including Gambia and Sierra Leone. The subsidiary will...