NTT DoCoMo Inc. announced Wednesday it has suspended sales of the P702i mobile phone due to a defect that causes the phone to lock when it is turned off.

The phone has a software glitch that permanently shuts the phone off when the user presses the power-off button, NTT DoCoMo said.

The FOMA third-generation cell phone is manufactured by Panasonic Mobile Communications, the cellular-phone arm of Matsushita Electric Industrial Co.

Since the handset's release in February, some 60,000 units have been sold and there has been more than 300 complaints from customers, the firm said.

NTT DoCoMo hopes to replace the phones by the end of the month.