Trading glitch stalls ASX

Update Australia's sharemarket halted trading more than an hour early today because of a technical glitch involving its new trading system.

The market effectively froze at about 2.48pm, east coast summer time, when confirmation of some trades failed to be sent as normal, prompting authorities to close the entire market, said ASX spokesman Matthew Gibbs.

"We are working to rectify the problem," Mr Gibbs said. ''Normal clearance and settlements processes will now take place.''

The ASX had considered extending trading to make up for lost time but has since dropped the plan while technicians work to fix the problem. Mr Gibbs declined to say whether trading would be able to resume as normal at 10am tomorrow.

''Before 10am, we'll know whether trading will resume,'' he said.

The initial problem surfaced at 2.18pm, according to the system status statement on the ASX website.

The benchmark ASX200 share index last traded at 4830.5 points, down 6 points or 0.1 per cent for the day. The All Ordinaries ended the day down 2.3 points at 4922.6.

The trading halt may disrupt the standard end of month balancing of portfolios, particularly for funds linked to the benchmark indexes.

For February, the ASX200 index ended up about 1.6 per cent, marking three consecutive monthly advances - the best run since the September 2009.

The ASX introduced its new trading system last November. Technicians are working to identify if the problem is related to the hardware or software systems, Mr Gibbs said.