** Interserve -21%, on track for worst day sincelate 2002 & top after British support services and constructioncompany takes 70 mln stg H1 charge
** Co says has been hit by cost overruns and delays in aenergy-from-waste contract in Glasgow; sees H1 & FY net debt 35mln stg higher than previous guidance
** Estimates under review and actually could go either way,Liberum says, hiking net debt est by c.10% to 347 mln stg & by70 mln stg to 360 mln stg in 2017
** Nearly half of 30-day avg vol through in first 10 mins
** 2017 net debt/EBITDA of 2.3x, makes prospect of capitalreturns or acquisitions less likely, Liberum adds