** M&S biggest loser on the FTSE & heads towards2-mth lows after seeing its Christmas blighted by onlinedelivery problems
** Posts 5.8 pct drop in underlying sales of clothing, gifts& home ware in Q3, far underperforming analyst expectations fora 3 pct drop
** Stock, down 2.4 pct, second most actively traded stock onFTSE100 behind Tesco which leads gains on UK benchmarkafter CEO Dave Lewis sets out plan for revival
** J Sainsbury & Wm Morrison up 3 pct & 2.2pct respectively (RM: tricia.wright1.thomsonreuters.com@reuters.net)
Tesco (TSCO)
Marks & Spencer (MKS)
Sainsbury's (SBRY)
