Nomura Holdings acknowledged on Friday that slack internal control led to a series of leaks of insider information in high-profile share offerings by Japanese blue-chip companies dating back to 2010, following an internal investigation into the matter.

Japan's largest brokerage said it will voluntary suspend part of its business operations for three to five days next week to take responsibility for the failure in compliance. Nomura also said its executive officer in charge of its institutional equity sales department and another executive officer in charge of compliance will step down, while the pay of senior executives will be cut.