Japan's benchmark Nikkei 225 Stock Average tumbled on Friday as market sentiment was undermined by the yen's rise and overnight heavy losses on Wall Street. The benchmark Nikkei 225 Stock Average lost 340.07 points, or 2.38 per cent, to end at 13,960.05, closing below the 14,000 mark for the first time in six months, dpa reported. The broader-based Topix index was down 15.4 points, or 1.34 per cent, at 1,134.09. For the week, the Nikkei fell 7.33 per cent and the Topix was down 6.73 per cent. Exporters traded broadly lower as the yen rose against the US dollar. A stronger yen makes Japanese-made goods less competitive abroad and erodes repatriated earnings. On Thursday, the US Dow Jones Industrial Average fell 1.62 per cent and the technology-heavy Nasdaq Composite Index lost 3.1 per cent on a sell-off of technology and biotech issues. In Tokyo, on currency markets at 3 pm (0600 GMT), the dollar traded at 101.61-62 yen, down from Thursday's 5 pm quote of 101.72-74 yen. The euro was quoted at 141.14-24 yen, up from 140.97-99 yen late Thursday, and at 1.3889-3892 dollars, up from 1.3858-3859 dollars.