HSBC, Citi and Morgan Stanley among five banks CMA investigated for competition law breaches between 2009 and 2013

The UK competition regulator has fined four major banks, including HSBC and Citi, more than £100m after it found traders had been using Bloomberg chatrooms to share sensitive information about government bonds.

The penalties follow a long-running investigation by the Competition and Markets Authority (CMA) that discovered that individual traders at Citi, HSBC, Morgan Stanley, Royal Bank of Canada (RBC) and Deutsche Bank had messaged rival bankers about the buying and selling of UK government bonds – known as gilts – on specific dates between 2009 and 2013.