It has also secured approval from minority shareholders to install a shareholders' rights or ''poison pill'' plan to protect ''all shareholders'' from coercive or creeping takeovers. Rio believes its contractual rights under a 2006 financing agreement have been breached by the moves and has taken the matter to arbitration. Eventually, Rio can get to 46 per cent of Ivanhoe at an all-up cost of about $US2.5 billion under the 2006 agreement that helped to finance Ivanhoe's share of Oyu Tolgoi project, the world's next big copper-gold mine. The 2006 agreement expires in October 2011. BARRY FitzGERALD