** Daily Mail bottom of the Stoxx &poised for biggest one-day drop since April 2009
** Co sees "marked deterioration" in British printadvertising market meaning FY to be at lower end of expectations
** Stock down 8.1% at levels not seen since mid March involume at a fifth of 90-day daily avg after just 15 mins oftrade
** DMGT join rivals Trinity Mirror & Johnston Press in warning of weaker ad markets (RM: tricia.wright1.thomsonreuters.com@reuters.net)