** Shares of Australia's Pro Medicus PME.AX extend losses from the previous session, down 5.8% to A$121.49
** Healthcare informatics co on Thursday reported half-year underlying EBITDA of A$93.7 million ($66.42 million), 8% below the Visible Alpha consensus estimate; stock fell 23.9% on the day
** Revenue of A$124.8 million also came in 4%-5% below VA consensus, according to Jefferies
** Stock set for worst week since late January 2012, down 22.9%
** YTD, stock down 45%
($1 = 1.4106 Australian dollars)
(Reporting by Shruti Agarwal in Bengaluru)
((Shruti.Agarwal@thomsonreuters.com))