The president of Nissan Motor has apologized after Japan's Fair Trade Commission told the automaker not to repeat its practice of unilaterally underpaying subcontracted suppliers.

Uchida Makoto spoke to reporters online on Wednesday.

The commission issued the advisory on March 7, saying unilaterally slashing predetermined prices to be paid to suppliers violates Japan's law on subcontractors.

The total estimated amount Nissan underpaid 36 subcontractors is about 3 billion yen, or about 20 million dollars.

Uchida said the company takes the advisory seriously, as what it did should never have happened.

He said he would like to apologize for causing enormous trouble to people in related industries and others.

Uchida said the company was insufficiently aware of the law, and will regularly check compliance and thoroughly train its employees.

The president said Nissan plans to offer explanations to parts suppliers, adding that it will be best for the company to respond to the matter sincerely.

Nissan plans to submit to the commission measures to prevent a recurrence.