** Shares of Medibank Private Ltd MPL.AX rise 9.2% to A$4.390

** Earlier in the day, stock hit a record high of A$4.420

** Stock is one of the top gainers in the benchmark index .AXJO

** The health company posts HY underlying NPAT of A$298.7 million ($188.33 million), up 13.8% from last year

** Co declares interim dividend of 7.8 Australian cents per share vs 7.2 cents last year

** Stock up 15.8% YTD, including moves in day's session

($1 = 1.5860 Australian dollars)

(Reporting by Jasmeen Ara Shaikh in Bengaluru)

((Jasmeenaraislam.shaikh@thomsonreuters.com))