(Updates with exchange reopening and stockbroker quote)
WELLINGTON, March 8 (Reuters) - The New Zealand stock exchange .NZ50 opening was delayed by 90 minutes on Wednesday due to a technical problem, likely reducing trading volumes for the day.
Bourse operator NZX Ltd NZX.NZ said it had "experienced issues" with its trading system and gateway connections, forcing a system restart.
Trading began just after 11.30 a.m. local time (2230 GMT Tuesday), delayed from the usual 10 a.m. start.
Jeremy Sullivan, a stockbroker at Hamilton Hindin Greene, said trading volumes were likely to be lower given many trades go through at the open and the close.
"It's not the first time and it probably won't be the last time we have a problem, computers aren't perfect," Sullivan said.
NZX spokeswoman Hannah Lynch did not immediately provide further details on the glitch and said it would be several days before the exchange publishes a report on the problem.
The NZX suffered several outages in 2014 owing to technical problems, on one occasion halting trading for three hours because of a glitch in the same system that caused Wednesday's issue.
Neighbour Australia has also had problems. A technical problem on the ASX .AXJO ASX.AX in September closed the bourse for several hours, infuriating traders.