** Shares of NXP Semiconductors NXPI.O slide about 8% premarket at $180.21 after CEO announces retirement
** Co says CEO Kurt Sievers will retire by year end and insider Rafael Sotomayor to take over in October
** NXP posts Q1 revenue beat, while Q2 rev forecast is largely inline with analysts' estimates
** 24 out of 31 analysts rate stock as "buy" or higher, 7 "hold"; Median PT is $240
** Of last close, NXPI down 5.6% YTD, while Philadelphia Semiconductor Index .SOX has fallen almost 15%
(Reporting by Twesha Dikshit)
((Twesha.Dikshit@thomsonreuters.com))