BUZZ-SIG: worst day ever on FY profit warning, CEO exit
** SIG (Stuttgart: QIG.SG - news) -23.5 pct, worst day ever, biggest loser on FTSE 250 as building materials supplier warns on FY profit, citing softer trading & intensified competition in the UK after Brexit vote
** Co adds CEO Stuart Mitchell steps down immediately
** Sees FY underlying PBT 75-80 mln stg, analysts' avg 91.53 mln stg, acc to Thomson Reuters I/B/E/S.
** Jefferies cuts to "hold" from "buy" & PT to 90p from 140p as it reduces FY PBT est by 18 pct to 75.3 mln stg
** Stock lowest since 2012, more than 5.3 mln shares traded, 2x 30-day avg vols gone through in first 30 minutes (Reuters Messaging: pranav.kiran@thomsonreuters.com@reuters.net)