Tokyo stocks fell Wednesday morning as some exporters were sold on a firmer yen amid growing speculation that the Bank of Japan could end its negative interest rate policy at its meeting next week. The 225-issue Nikkei Stock Average fell 161.39 points, or 0.42 percent, from Tuesday to 38,636.12. The broader Topix index was down 10.25 points, or 0.39 percent, at 2,646.99. The U.S. dollar weakened to the lower 147 yen range in Tokyo on yen buying after major Japanese firms offered the largest pay hikes in decades in annual wage talks, in a move that could pave the way for the BOJ to shift from i…