re: Ann: FORM 604 NOTICE OF CHANGE OF INTERES... They've reduced their holding by 0.15% in the last couple of days. Nothing to get excited about.
Since M&G are the largest major shareholder behind RIO I think its a good sign they are still holding. I doubt they would wait for 11c to start dumping 93m shares on the market.
Franklin & Vangaurd both own 5% of the stock and one or both of these could be the 'mystery seller'