Tokyo stocks finished lower for a fourth straight session Wednesday, dragged down by continued sell-offs on concerns about slower growth in the global economy and corporate earnings, Nikkei.com reported. The Nikkei Stock Average ended the day at 8,746.87, down 39.18 points, or 0.45%, touching its lowest level since Sept. 6, when the gauge reached 8,680. Cyclical issues and China-tied stocks marked fresh 2012 lows. The benchmark index rose slightly in the morning, helped by a pause in the yen's advance. But it remained top-heavy and gradually weakened midway through the afternoon as short-term funds started unwinding their positions in stock index futures.