• Shares of Australia's Antilles Gold rise as much as 37.5% to A$0.011, hitting their highest since June 4

• Shares mark their biggest intraday pct gain since June 22

• Gold miner signs pact with Luxembourg-based alternative investment group GEM Global Yield

• GEM will acquire 25% stake in Antilles Gold's Cayman Islands unit, which owns 50% interest in Cuban joint venture mining company Minera La Victoria

• Stock flat YTD

(Reporting by Subhalakshmi Dey in Bengaluru)