BUZZ-Antofagasta: Citi double upgrade spurs rally
** Antofagasta (Other OTC: ANFGF - news) rises 5.9 pct after Citi upgrades to "buy" from "sell"
** Says stock is unusual in mining sector for its strong balance sheet, ability to survive at current spot prices and high exposure to copper
** Stock down 75 pct over last three years; Citi says EV/EBITDA of 7.2x now attractive v BHP Billiton (NYSE: BBL - news)
** Among top risers on Stoxx 600
(RM (LSE: RM.L - news) : alasdair.pal.thomsonreuters.com@reuters.net)