** Shire shares slammed after AbbVie saysit is reconsidering deal.
** Sharpest one-day drop for Shire shares since Feb 2002wipes off $14 bln in its market value and takes stock right backwhere it was when news of AbbVie deal first broke in June.
** Even after drop Shire is second-best performing stock onFTSE 100 this year, still up 31 pct, slightly behind the33 pct rise for Dixons Carphone.
** As M&A premium disappears attraction of healthcare sector- best performer across Europe & the U.K. this year - remains.
** AstraZeneca, down 3.9 pct, & Smith & Nephew, down 2.4 pct, both feeling the heat and round out thetop-3 losers on the FTSE on the day.
(RM: vikram.subhedar.thomsonreuters.com@reuters.net)