TOKYO, March 12 (Xinhua) -- Tokyo stocks extended gains Tuesday morning on hopes that Britain's exit from the European Union will be a smooth one, with the market mood also buoyed by robust U.S. retail sales data lifting Wall Street overnight.

The 225-issue Nikkei Stock Average gained 396.52 points, or 1.88 percent, from Monday to 21,521.61.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, added 27.38 points, or 1.73 percent, at 1,608.82.

Electric appliance, securities house and real estate-linked issues comprised those that gained the most by the morning break.