** Shares of Web Travel Group WEB.AX rise as much as 14.2% to A$4.83, their biggest intraday gain since May 22

** Stock hits its highest level since Oct. 14

** Business travel distribution co posts half-year revenue of A$170.4 mln ($110.30 mln), up 1% year-on-year

** Announces share buy-back of up to A$150 mln

** Stock down 27.8% YTD, including session's move

($1 = 1.5449 Australian dollars)

(Reporting by Aaditya Govind Rao in Bengaluru)

((Aaditya.govindrao@thomsonreuters.com;))