SYDNEY (Reuters) - Global miner Rio Tinto <RIO.AX> <RIO.L> wrapped up one of the world's biggest rights issues on Friday, saying its Australian shareholders had taken up 94.76 percent of their entitlements to the new shares. On Thursday, UK shareholders had taken up 96.97 percent of the deeply discounted, fully underwitten $15.2 billion rights offer, the fifth-biggest on record, putting the indebted Anglo-Australian group on a firmer financial footing. The issue also marks a bonanza for the banks that underwrote it ...