** Argus Research raises rating on U.S.-listed shares of mining giant BHP Group BHP.N to "buy" from "hold"

** Brokerage says co's performance is tied to iron ore, copper and coal prices, which are firming as global economy improves

** With China's recovery lifting iron ore and clean energy demand boosting copper, stock showing signs of trend reversal, Argus Research says

** As of last close, BHP up 23.6% YTD

(Reporting by Varun Sahay in Bengaluru)

((Varun.sahay@thomsonreuters.com))