Sept 7 (Reuters) - Rio Tinto (LON:RIO) Ltd RIO.AX
* increase to kestrel ore reserves-rio.ax
* Increased estimates of rio tinto coal australia's coal reserves at Kestrel underground Longwall mine in Queensland, Australia
* Kestrel ore reserves have increased by 62 mt, from 123 mt to 185 mt.
* Kestrel mineral resources exclusive of ore reserves have decreased by 65 mt, from 306 mt to 241 mt