By Mai Iida, BridgeNews Tokyo--Jan. 11--The Nikkei 225 Stock Average ended at 13,201.07 Thursday, its lowest close since October 1998. Influenced by strong concerns over the near-term outlook of local equities, and pessimism stemming from the sharp fall in Yahoo! shares in after-hours trading, the Nikkei fell 231.58 points, or 1.7%.