The Government Pension Investment Fund said Friday it has filed a suit against Seibu Railway Co., its parent, Kokudo Corp., and Yoshiaki Tsutsumi, the former head of Kokudo, for investment losses suffered after the railway was delisted over the falsification of it financial reports.

The investment fund lodged the suit with the Tokyo District Court, demanding a combined 18.55 billion yen in damages.

The fund listed seven trust banks, including Mitsubishi UFJ Trust Banking Corp. and Mizuho Trust & Banking Co., which were in charge of managing its funds, as plaintiffs.

Last October, Seibu Railway admitted it had been falsifying the names of its stockholders in its financial reports, using the names of several individuals instead of Kokudo.

The falsification resulted in the company being delisted from the Tokyo Stock Exchange in December. Tsutsumi is now standing trial over the falsifications and for insider trading.