U.S. authorities scrutinise Rio's 2013 coal writedown - sources
November 29, 2016 at 05:41 AM EST
SYDNEY, Nov 29 (Reuters) - The U.S. Securities and Exchange Commission is investigating a $3 billion impairment charge booked by miner Rio Tinto in 2013 on the value of a Mozambican coal asset, two sources familiar with the matter said on Tuesday.
