Investors stand in front of a screen showing the logo of Nomura Holdings in Tokyo, Japan, in this December 1, 2015 file photo. REUTERS/Toru Hanai/Files

TOKYO (Reuters) - Japan’s financial watchdog on Tuesday ordered Nomura Holdings to improve its business practices after the country’s biggest brokerage admitted an employee had leaked market information.

The Financial Services Agency said it had issued one of its “business improvement orders” against Nomura, a regulatory punishment that requires firms to submit a plan detailing how they will improve internal controls.

Nomura on Friday confirmed that information related to listing and delisting criteria now under review by the Tokyo Stock Exchange had been handled improperly. It has said that its chief executive would take a 30% pay cut for three months to take responsibility for the leak.

“We deeply regret for what had happened and take the business improvement order seriously,” Nomura said in a statement.

“We sincerely apologize for causing great trouble for our clients and other stakeholders and having caused them to worry.”

Nomura had said an employee from its Nomura Research Institute affiliate leaked information about the expected changes to the chief strategist of its securities arm, who informed sales staff. The sales staff, in turn, told clients, Nomura has said.

While the punishment does not include a fine, the incident marks the latest headache for CEO Koji Nagai as he struggles to turn around the investment bank. Nomura last month reported its first annual loss in a decade and said it would not pay out bonuses to directors.

Nomura said it would submit its first plans to improve business practices by June 4.