Nikkei opened 0.85 percent higher Monday supported by a weaker yen and the result of the Tokyo metropolitan assembly election, in which the ruling Liberal Democratic Party won. At 9:15 a.m., the 225-issue Nikkei Stock Average was up 112.09 points, or 0.85 percent, from Friday at 13,342.22. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was up 9.51 points, or 0.87 percent, at 1,108. 91.