shares of rio tinto plc rio inched down 098 to £5634 friday on what proved to be an allaround dismal trading session for the stock market with the ftse 100 index ukx falling 167 to 774835 rio tinto plc closed £772 short of its 52week high £6406 which the company achieved on january 26 trading volume 23 m remained 13 million below its 50day average volume of 35 m editors note this story was autogenerated by automated insights an automation technology provider using data from dow jones and factset see our market data terms of use