Stocks ended in negative territory Monday in Tokyo, weighed down by the yen's continued strength against the U.S. dollar and lingering concerns over risks to economic ties between Japan and China. The 225-issue Nikkei Stock Average dropped 40.71 points, or 0. 45 percent, from Friday at 9,069.29. The broader Topix index of all First Section issues on the Tokyo Stock Exchange lost 2.70 points, or 0.36 percent, to 753.68. Major losers included sea transport firms, steelmakers and rubber product makers, while utility suppliers, real estate developers and telecommunications companies posted gains. Turnover during the day's trading reached 0.9133 trillion yen ( 11.7 billion U.S. dollars).