Tokyo stocks opened lower Thursday as investors locked in gains following their four-day winning streak. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 264.14 points, or 0.96 percent, from Wednesday to 27,269.46. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was down 12.12 points, or 0.63 percent, at 1,924.44. Decliners were led by electric appliance, air transportation and machinery issues. At 9 a.m., the dollar fetched 114.38-39 yen compared with 114.37-47 yen in New York and 114.62-64 yen in Tokyo at 5 p.m. Wednesday. The euro w…