BUZZ-ITV: retreats from 15-yr highs after update
** ITV (LSE: ITV.L - news) falls back from 15-yr highs hit recently in decent volume after issues Q1 trading update
** Net advertising revenue up 12 pct in Q1, slightly ahead of analyst expectations; NAR expected to be up 5 pct in H1
** Stock had strong recent run, 4th-top UK blue-chip performer YTD, up c.24 pct; market participants flag high expectations into numbers
** Stock, down 2.6 pct, 3rd-top FTSE 100 faller (behind Sainsbury & Kingfisher which are both trading ex-dividend ) (RM (LSE: RM.L - news) : tricia.wright1.thomsonreuters.com@reuters.net)