* Australia's bourse blames hardware failure for trading turmoil
* Share trading opens late and closes early
* No sign on a cyber security breach (Adds ASX statement on cause of halt to trading, other comments)
By Tom Westbrook
SYDNEY, Sept 19 (Reuters) - The Australian Securities Exchange ASX.AX said hardware failure in its main database caused Monday's opening to be delayed by more than an hour and cut short the afternoon trading by about 90 minutes, reducing turnover and infuriating traders.
The shutdown is the most serious glitch for the exchange since the bourse shut for four hours in October 2011, when it suffered a connectivity problem. The market also suspended trades for 30 minutes in February, due to a glitch.
"What happened today does not meet the high standards of operations and system reliability that we set ourselves, and that our customers should rightly expect of us. We apologise for the disruption," ASX said in a statement.
The exchange said it was "now focused on ensuring that the market re-opens on schedule tomorrow morning".
The ASX was the world's ninth largest stock exchange as of 2011, according to World Stock Exchanges website.
Monday's woes "will cost the whole industry", Mathan Somasundaram, a quant strategist at stockbroker Baillieu Holst said. "We have a lot of turnover on an average day and obviously all our advisors will lose that turnover over the day."
The ASX's typically operates from 10 am to 4 pm local time, but on Monday pre-open trading did not begin until 11.10 am.
In a statement on the morning snag, the ASX said the opening of the equities market was delayed "due to an issue with a component that allows ASX to manage individual stocks", and that the problem had been resolved. But the bourse again halted trade shortly after lunch before announcing it would close the exchange for the day at 1:37 local time (0337 GMT).
The issue was not related to cyber security, the ASX added.
Bonds and futures also trade on the exchange, but their trading was not disrupted by Monday's glitch.
The benchmark S&P/ASX 200 index .AXJO was flat at 5,294.8 points when the bourse announced that trading would not resume.