METALS-London copper near highest in three weeks on supply worries

(Adds comment, detail; updates prices) By Melanie Burton MELBOURNE, May 26 (Reuters) - London Metal Exchange copper hovered near its highest in three weeks on Friday, supported by supply concerns after news of further disruption at Indonesia's Grasberg, one of world's biggest copper mines. Freeport McMoRan Inc said on Thursday that mining and milling rates at its Grasberg mine in Papua, Indonesia have been affected by an extended strike, and a "large number" of about 4,000 absentee