Tokyo shares ended the morning session sharply lower on Thursday withJan. benchmark Nikkei index tumbling over 3 percent, following a plunge in the U.S. market overnight after the U.S. Federal Reserve cut its stimulus scale. The 225-issue Nikkei Stock Average plunged 511.53 points, or 3. 33 percent, from Wednesday to 14,872.38. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was down 38.15 points, or 3.04 percent, to 1, 218.03. Decliners were led by real estate and insurance shares.