UPDATE 2-Wendy's/Arby's misses, warns of rising beef costs

mln * Shares down 2.5 percent (Adds CEO quote, share move) NEW YORK, May 10 (Reuters) - Wendy's/Arby's Group Inc's (WEN.N The No. 3 U.S. fast-food restaurant operator, whose shares fell 2.5 percent, cut its adjusted earnings profit forecast for the year...