Mining behemoth Rio Tinto has exercised its right to acquire more shares in Asia-Pacific focused miner Ivanhoe Mines, taking its stake up to 48.5% from 46.5% previously.The price paid per share was C$18.98 and the total consideration for the exercise of this subscription right was C$529.5m. Rio Tinto's current maximum permitted shareholding in Canadian firm Ivanhoe Mines under the terms of existing contractual arrangements between the two companies is 49%. Ivanhoe's core assets are its 66% interest in the world-scale Oyu Tolgoi copper and gold mine development project in southern Mongolia; its 57% interest in Mongolian coal miner SouthGobi Resources; its 62% interest in Ivanhoe Australia, which is developing the Merlin molybdenum-rhenium project in Australia; and its 50% interest in Altynalmas Gold, which is developing the Kyzyl Gold Project in Kazakhstan. --jh