The head of the Tokyo Stock Exchange has stepped down after accepting responsibility for an unprecedented day-long shutdown of one of the world's biggest markets, the operator said Monday.

A hardware glitch suspended transactions for a day on Tokyo's two leading indexes last month, as well as smaller exchanges in other parts of Japan.

TSE president Koichiro Miyahara "has taken seriously his responsibility for the failure in the... trading system," the Japan Exchange Group (JPX), which operates TSE, said in a statement.

Miyahara "has requested to resign from his position as President & CEO of TSE and all other held positions within the Group, effective on November 30," it said.

The CEO of JPX, Akira Kiyota, will temporarily take over the position with a 50 percent pay cut for four months, the statement said.

A hardware glitch caused transactions to be suspended for an entire day on Tokyo's two leading indexes last month
A hardware glitch caused transactions to be suspended for an entire day on Tokyo's two leading indexes last month AFP / CHARLY TRIBALLEAU

JPX and TSE were also served a business improvement order by Japan's Financial Services Agency.

Last month Tokyo market operators said there was no indication of a cyberattack, and the problem had been traced to a memory breakdown that failed to properly trigger a switch to a back-up system.

They said the faulty hardware had been replaced, and that personnel would be deployed to monitor the system to avoid a repeat.

JPX is the globe's third-largest exchange by market capitalisation, at an estimated $5.1 trillion, including listings on exchanges outside Tokyo.

It sits behind only the New York Stock Exchange and Nasdaq, according to the World Federation of Exchanges.

Japan Tokyo Stock Exchange