Tokyo stocks ended lower Thursday, weighed down by caution over upcoming earnings reports and projections from major technology firms amid concerns about slowing growth in the semiconductor industry. The 225-issue Nikkei Stock Average ended down 269.11 points, or 0.69 percent, from Wednesday at 38,911.19. The broader Topix index finished 2.83 points, or 0.11 percent, lower at 2,687.83. On the top-tier Prime Market, decliners were led by precision instrument, nonferrous metal and chemical issues. The U.S. dollar remained strong, mostly in the mid-149 yen range in Tokyo, on buying supported by p…