(Adds details on Whitesides appointment, share movement)
   July 15 (Reuters) - Billionaire Richard Branson's Virgin Galactic Holdings Inc on Wednesday named Walt Disney Co  executive Michael Colglazier as its new chief executive officer, sending its shares up 4.3% in extended trade.
   Colglazier, who was previously president and managing director at Disney Parks International, will replace George Whitesides, who joined the company in 2010 as its first CEO. 
   Virgin Galactic said Whitesides will step down from its board and take over as chief space officer. Both appointments are effective from July 20.
   The move comes after Virgin Galactic in June announced it had successfully completed the second SpaceShipTwo test flight from Spaceport America, as the company prepares for commercial service.
   The space tourism company, which competes with billionaire-backed ventures such as Amazon.com Inc's  Blue Origin, offers zero-gravity experiences to customers and has long-term point-to-point travel plans to quickly transport passengers from city to city at near-space altitudes.
    

(Reporting by Sanjana Shivdas in Bengaluru; Editing by Aditya
Soni and Ramakrishnan M.)
((SanjanaSitara.Shivdas@thomsonreuters.com; within U.S. +1 646
223 8780, outside U.S. +91 80 6749 1642; Twitter:
@SanjanaShivdas;)