Nakai Securities Co. reported Friday to the Kinki Local Finance Bureau that it will voluntarily shut down.

The Osaka-based regional brokerage, capitalized at 502 million yen, will stop part of its operations from Monday and begin returning deposited assets to clients. It was not affiliated with any major brokerage house.

Nakai officials said they determined that the brokerage would not be able to weather the deregulation of the securities market, such as the full liberalization of commissions on securities transactions.

It marked the fourth securities firm based in the Osaka area to voluntarily close during the current fiscal year against the backdrop of deregulation and the prolonged economic slump.