TOKYO, Sept 30 (Reuters) - Japan's Nikkei average opened almost flat on Thursday, after Wall Street took a breather from a month-long rally, but the index is poised to book its best monthly performance in six months.
The benchmark Nikkei fell 4.55 points to 9,554.83, on course to post gains of about 8 percent for the month of September, which would be its biggest monthly rise since March.
The index has received help from expectations for further easing by the central bank and that the yen's rapid advance could be curbed by more intervention by the authorities.
The broader Topix was nearly unchanged at 846.86. (Reporting by Aiko Hayashi; Editing by Joseph Radford)