UK's Big Technologies shares fall on call to oust Chairman
** Shares of monitoring services provider Big Technologies BIGB.L down 2.1% at 83 p ** Co receives requisition to hold a general meeting seeking removal of Chairman Alexander Brennan from the board ** Requisitioners call to appoint James Graham Matheson to the board as a director and Chairman with immediate effect ** BIGB has been locked in a legal dispute with its former chief executive officer ** Including session's losses, stock down ~ 40% YTD (Reporting by Simone Lobo)