Feb 21 (Reuters) - KGHM Polska Miedz SA KGH.WA :
* Europe's No. 2 copper miner, the Poland-based KGHM, says tests have indicated impairment charges worth $90 million to be sustained by the company in 2017
* KGHM says tests have shown that an impairment charge worth $118.3 mln related to the Canadian Sudbury project is justified
* An impairment charge worth $64 mln related to the Canadian Ajax project is also justified, KGHM says
* KGHM also says reversal of some of $92.7 mln of an impairment charge related to the U.S. Robinson mine is justified
* KGHM says the final value of the impairment charges could still change
* Says tests have not shown justification to change the estimated value of KGHM's other mining assets