TOKYO -- The Tokyo Stock Exchange has begun weighing a proposal to lengthen cash stock trading hours by 30 minutes to 3:30 p.m., according to people familiar with the matter, in hopes of boosting its appeal to international investors.

The TSE's current trading day of 5 hours is shorter than that of the New York and Singapore exchanges.

If adopted, the longer trading day would be expected to take effect in 2024, when the market's trading system is scheduled to be updated. It would be the first extension since 1954.

A proposal for a one-hour extension has also been put forward, but people familiar with the matter said 30 minutes would be the likelier choice. A decision is expected in October.

The move comes as Japan's leading stock market looks to raise its international competitiveness as trading volume growth plateaus.

The opening bell rings at 9 a.m. and the close comes at 3 p.m., with a one-hour lunch break in between. Ending this lunch break was debated in the past but never approved.

The TSE has considered extensions three times in the past, but opposition from brokerages and other stakeholders scuppered each attempt.