Image caption It is the second time this year that the exchange has suffered technical problems

The Australian Securities Exchange (ASX) has resumed trading after a technical glitch forced a halt just as the market opened.

The suspension, which lasted for almost four hours, applied only to equities and did not affect commodities or currency trading.

The halt came days before the launch of a rival exchange in Australia by Chi-X.

It is the second time this year that technical issues have closed the exchange.

In February, a glitch led to a suspension in trading that lasted just over an hour.

ASX spokeswoman Leeanne Bland declined to comment on whether this incident was related.

She said the exchange would now undertake a more detailed analysis of Thursday's glitch to ensure it does not happen again.

Ms Bland told the BBC the suspension went into effect five minutes after the market opened, when it became apparent that some brokers could not connect to the ASX trading system.

The exchange then worked with its technology supplier Nasdaq OMX to resolve the issue.

In the financial year ending June 2011, the ASX saw an average of 570,440 daily trades with a value of 5.3bn Australian dollars ($5.6bn; £3.5bn).

Trading on Thursday was halted after just 6,700 trades.