** Shares of payments firm Shift4 Payments slide 11% to $101.61

** President-elect Donald Trump taps FOUR CEO Jared Isaacman to lead NASA

** Benchmark believes FOUR President Taylor Lauber is the most likely candidate to succeed Isaacman as the CEO

** William Blair believes investors should add to FOUR given the weakness in stock as its believes franchise value outweighs uncertainty over around succession

** Brokerage says FOUR could again become an attractive acquisition candidate for potential strategic buyers, including payments firm Fiserv

** As of last close, FOUR shares up 53.6% YTD

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com))