The Bank of N.T. Butterfield & Son Limited has amended its buy-back programme for preference shares, according to a press release from the Bermuda Stock Exchange yesterday.It stated that at a meeting of a committee of the board of the Bank it was resolved that the Bank revise the preference share repurchase programme by increasing the number of preference shares sought from 8,000 to 9,639. The meeting was held on June 4.The Bank’s buy-back programme for common shares remains unchanged.Butterfield has a primary listing on the Bermuda Stock Exchange, on which its common shares and preference shares trade actively. Butterfield maintains a secondary listing on the Cayman Islands Stock Exchange.Useful website: www.bsx.com