Tokyo stocks opened higher Monday as export-related issues were lifted by the yen’s recent weakness against the U.S. dollar. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average rose 310.19 points, or 0.78 percent, from Friday to 39,893.27. The broader Topix index was up 25.92 points, or 0.92 percent, at 2,835.55. On the top-tier Prime Market, other gainers included insurance, marine transportation and real estate issues. At 9 a.m., the dollar fetched 160.91-94 yen compared with 160.84-94 yen in New York and 160.92-94 yen in Tokyo at 5 p.m. Friday. The euro was quoted at $1.0…