TOKYO, Dec 16 (Reuters) - Japan's Nikkei average traded flat for a fourth straight session on Thursday as optimism over the dollar's rise to a near three-month high against the yen the previous day was offset by worries over euro zone debt and overheating in the market.
The Nikkei has been trapped in a narrow 190 point range for over a week as domestic investors aggressively took profits on its rally of around 12 percent since the beginning of November, while foreign investors continued buying financial shares seen as undervalued.
The benchmark Nikkei added 1.51 points or 0.01 percent to close at 10,311.29 while the broader Topix index gained 1.42 points or 0.2 percent to 903.84. (Reporting by Antoni Slodkowski and Ayai Tomisawa; Editing by Michael Watson)