** Shares of contract research firm ICON ICLR.O fall 5.8% to $169.5 premarket

** CEO Dr. Steve Cutler is retiring; COO Barry Balfe to replace him on October 1 and join the board, company says

** Dr. Cutler will continue to serve on the board as a non-executive director

** In August, a next-generation COVID-19 vaccine study, ICON was running, had been paused by U.S. funding agency BARDA after it issued a stop-work notice to the study sponsor

** As of last close, ICON stock down 14.2% YTD

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com))