The Nikkei index extended gains in mid- afternoon trading on Tuesday, briefly rising more than 2 percent on gains in heavyweights and a weakening yen. At 2:15 p.m., the 225-issue Nikkei Stock Average was up 599.25 points or 1.99 percent, at 30,683.40 after rising to as high as 30,714.52. The index's gains follow its highest closing in over 30 years Monday.
