** Webjet slips as much as 13% to A$0.735, lowest since Nov. 5
** Stock logs worst session since Nov. 20
** Travel firm sued by Australian competition watchdog ACCC, alleging co misled consumers about flight prices and bookings
** Stock down 18.6% vs opening price on Sept.23, when it was listed
(Reporting by Rajasik Mukherjee in Bengaluru)
((Rajasik.Mukherjee@thomsonreuters.com;))