Moody's has downgraded its outlook for the U.K. banking sector to negative from stable due to the expected impact of the U.K.'s decision to leave the European Union. The credit agency also downgraded their outlook for 12 U.K. banks and building societies, including Lloyds , Barclays and HSBC . It did not downgrade its outlook for the Royal Bank of Scotland. Moody's expects the decision to leave the EU will reduce the profitability of the U.K.