BENGALURU (REUTERS) - Exchange operator Nasdaq on Friday (Dec 4) apologised for an Australian stock exchange outage last month, which wiped out nearly a full session of trading.

"We take our role as a provider of mission-critical technology seriously and apologise to ASX (Australian Securities Exchange), its customers and all those impacted," Nasdaq chief executive officer Adena Friedman said.

Australia's central bank and corporate regulator had expressed concerns over bourse operator ASX's trading systems after the glitch halted trade on Nov 16.

ASX and its technology provider Nasdaq said they had identified the root cause of the outage as a software issue that caused incorrect functionality in the tailor made combinations (TMC) order book.

TMC is a tool primarily used by retail and institutional traders of equity derivatives which enable the trading of multiple options in one transaction, the companies said.

ASX said it plans to reintroduce some TMC functionality on Dec 21.