The Tokyo Stock Exchange is making preparations to extend the trading day by 30 minutes in about three years time, NHK reported, citing unidentified people.

The report comes after the exchange formed a working group earlier this year to discuss extending trading hours past the current 3 p.m. close. That body is set to compile a report by around October.

The Tokyo bourse now trades between 9 a.m. and 3 p.m., with a lunch break between 11:30 a.m. and 12:30 p.m., making the five-hour trading day considerably shorter than many other regional rivals. The change would be made along with its next large upgrade of trading systems, the report said.

If realized, longer hours would be the first significant change in trading in Tokyo in over a decade. The exchange shortened its lunch break by 30 minutes to the current one hour in 2011. NHK said that it would be the first time to extend the closing time since 1954, when it was changed from 2 p.m. to 3 p.m.

"Nothing has been decided at this point,” a spokesperson for Japan Exchange Group Inc. said. "While there are various options, the working group is currently discussing what form the extension will take.”

"The Tokyo Stock Exchange has been seen as wanting to lengthen trading hours,” said Tomoichiro Kubota, a senior market analyst at Matsui Securities Co. in Tokyo. "Online brokerages have surveyed retail investors in the past, and there was positive response for longer trading hours.”

A recommendation in 2014 for the exchange to consider an evening session failed to result in changes, after the plans were dropped following opposition from traditional brokerages, who said longer hours would increase costs.