Yasuhiro Sato, chairman of the Japanese Bankers and president of Mizuho Financial Group, also said at a regular news conference he did not believe Japanese banks were involved in the manipulation of the London interbank offered rate, Libor.

Confidence in Libor, a benchmark that underpins transactions worth trillions of dollars, has been shaken by revelations that bankers manipulated the rate to profit on trades and hide their own borrowing costs during the 2007-09 financial crisis.

The Japanese banking lobby has asked the 18 banks contributing to Tibor to check whether proper procedures are being followed in submitting rates.

"We don't think there's any problem with (Tibor), but we decided on a check given growing public interest in Libor," the association's director, Shin Takagi, told a meeting of ruling party lawmakers on Thursday.

(Reporting by Taiga Uranaka; Editing by Michael Watson)