Mumbai, June 17 -- Inventories of major base metals continue to decline in a key global trading hub. The Organization of Petroleum Exporting Countries or OPEC stated that its base metal index rose 3.1%, m-o-m, in May. Metal prices received support from Chinese stimulus measures aimed at supporting economic growth. Supply tightness in key metals, such as aluminium and copper, also contributed to the upward momentum. However, softer global industrial activity capped gains. At the London Metal Exchange (LME) warehouses, combined stocks of base metals declined for a fifth consecutive month in May, falling by 4.6%, m-o-m, and were down by 24.6%, y-o-y. Combined cancelled warrants fell for a second consecutive month in May, dropping by 21.1%, m-o...