The number of listed companies that posted extraordinary losses in connection with the March 11, 2011, earthquake and tsunami has reached 1,356, with the combined amount totaling ¥4.07 trillion, according to data compiled by credit research firm Tokyo Shoko Research Ltd.

The data, compiled from losses posted in the business year that ended last March 31 or afterward, showed that the company which suffered the most was Tokyo Electric Power Co., operator of the wrecked Fukushima No. 1 nuclear plant.

Tepco posted losses of ¥2.1 trillion in the full-year period that ended last March and the ensuing half-year through Sept. 30, accounting for more than half of all losses tallied by the credit research firm.

Tepco was followed by Tohoku Electric Power Co., with ¥173.1 billion in losses, and JX Holdings Inc., whose oil refineries suffered in the disasters, with ¥137.4 billion in losses.