The Singapore Exchange failed to open today after a technical glitch halted trading.
"The securities market will not resume trading at 16.00 hours and will not re-open today," it said in a fifth update.
South East Asia's largest stock market had already missed a self-imposed deadline of 14.00pm earlier.
"Member reconciliation files are being generated and the securities market will not resume trading at 14.00pm. We will advise the market resumption time once member reconciliation is completed," it said.
The market, worth nearly $500bn, was shut due to duplicated trade confirmation messages being generated. It was put in an "adjust phase" at 11:38am Singapore time, the exchange said.
"No duplicate trades were executed and the market remained orderly," it added.
The exchange also apologised for any inconvenience caused, and advised the public to check its website for updates.