A three-decade bank veteran and currently co-chief operating officer, Okuda, 56, is tasked with remaking Nomura into a firm that can better compete with the hordes of fintech and other non-traditional rivals breaking into financial services.

Never realising its ambition of becoming a global investment bank or even gaining a strong footing after its 2008 disastrous acquisition of Lehman Brothers' Asian and European businesses, Nomura last year posted its first annual loss in a decade.

In April, it announced $1 billion in cost cuts for its wholesale business, which serves corporations and institutional investors, and said it would shut 20% of domestic retail branches.

"I have a sense of crisis over whether today's main players in the financial industry can remain so down the road," Okuda told a gathering of investors, a day after he was named to succeed CEO Koji Nagai from April.

"I want to speed up our pace of reform, taking it into account the change that is affecting our customers and financial markets," he said.

Okuda did not go into details. But a senior company source said the bank was likely to first sharpen its focus on its domestic retail business as that has the potential to be a strong source of revenue generation for the bank in the next few years.

In Nomura's strategy update to investors in April, Okuda said the bank needed to overhaul its wholesale business structure and reduce lower growth, lower profitability businesses.

To date, he has been mainly focused on Nomura's investment banking business, which has been hit by a shrinking fee pool as banks chase fewer deals as well as by new regulations that have increased costs.

While Nomura is expanding into China, with its majority-owned securities joint venture securing regulatory approval last month, boosting revenue from overseas businesses will remain a challenge said the company source, who was not authorised to speak on the matter and declined to identified.

Overseas, Nomura remains a mid-sized player seeking to compete with much larger and better established U.S., European and homegrown rivals in those markets.

By Takashi Umekawa and Sumeet Chatterjee