Tokyo--Feb. 13--Share prices on the Tokyo Stock Exchange ended the morning lower in lackluster trade with investors worrying about a slowing in earnings growth in high-technology firms. Although the Bank of Japan's announcement Friday of a cut in the official discount rate supported gains in the banking sector, the central bank's move failed to bolster the overall stock market. The Nikkei fell 70.26 points, or 0.5%, to 13,352.57.