BUZZ-Australia's Navitas hit 2-1/2 year low on poor outlook for enrolment growth
(Corrects shares hit 2-1/2 year low, not all-time low)
** Education provider Navitas Ltd's shares fall as much as 11.2 pct to 2-1/2 year low
** Says government changes to visa refusal rate in U.K. impacted enrolments for second semester
** Adds Australian and U.K. colleges face challenges which are impacting enrolment growth in the short term
** Shares (Berlin: DI6.BE - news) on track for biggest percentage fall since Feb 4, 2015
** Stock top percentage loser on S&P/ASX 100 Index
(Reuters Messaging: shashwat.pradhan.thomsonreuters.com@reuters.net)