Tokyo, June 5 (Jiji Press)--Japan's benchmark Nikkei 225 stock average briefly plummeted over 1,200 points Friday morning, due to selling pressure on semiconductor-related issues. At 9:14 a.m., the index of 225 selected issues listed on the Tokyo Stock Exchange's Prime section stood at 66,209.32, down 1,261.37 points, or 1.87 pct, from the previous day. After high-tech stocks declined in the U.S. market overnight, selling of chip-related shares dominated the Tokyo market Friday. END [Copyright The Jiji Press, Ltd.]