** Shares of Etherstack ESK.AX rise as much as 28.3% to A$0.77, hitting their highest level since December 7, 2020
** Stocks marks its biggest intraday pct gain since October 16
** UK-based wireless tech firm's unit wins A$2.5 million ($1.62 million) defence contract with the Commonwealth of Australia for advanced defence communications
** About 509,000 shares change hands, 4.2x the 30-day average
** Stock has more than tripled in value so far this year
($1 = 1.5389 Australian dollars)
(Reporting by Ananya Verma in Bengaluru)
((ananya.verma@thomsonreuters.com;))