** Shares of Australia's DroneShield DRO.AX extend gains to rise as much as 6.7% to A$3.2, their highest level since November 12
** Stock among top gainers on the ASX 200 benchmark
** Drone technology firm said on Monday it will undertake immediate action following an independent review of co's continuous disclosure and securities trading policies and other areas
** Says board will establish mandatory minimum shareholding policy for all directors and members of senior management and update co's securities trading policy, others
** Says reviewing the director and executive remuneration framework
** Measures follow a sharp sell-off in late November after stake sales by top executives, a contract disclosure error, and the abrupt exit of its U.S. head
** Stock up more than 300% YTD
(Reporting by Sneha Kumar in Bengaluru)
((Sneha.kumar@thomsonreuters.com;))