No details on the cause of the TSE problem - which hit at around 09:20 local time, halting derivatives trading for an hour and a half - have been provided.

This is the second major outage to affect the bourse this year - in February president Atsushi Saito and several of his top executives had their pay docked over a systems failure that saw trading suspended for several hours.

The Tokyo glitch comes a day after trading in Spanish equities was halted for more than four hours because of a, so far unidentified, BME systems failure.

The problems also occur as the markets' reliance on computer systems is once again in the spotlight thanks to last week's disastrous Knight Capital software malfunction and the earlier Nasdaq OMX Facebook IPO debacle.