Toronto, Ontario--(Newsfile Corp. - November 19, 2012) -  The following issues have been halted by IIROC:Company:  NuVista Energy Ltd.TSX Symbol: NVA (all issues) Reason:Pending News Halt Time (ET)08:18  IIROC can make a decision to impose a temporary suspension of trading in a security of a publicly listed company, usually in anticipation of a material news announcement by the company. Trading halts are issued based on the principle that all investors should have the same timely access ...