The ASX has been forced to delay the rollout of changes to key trading services, including the move to a single opening time for stocks, in a blow to its attempts at showing regulators it can handle critical upgrades.

The bourse told stockbrokers and other market players the to so-called ASX Trade Service Release 15 will not go live as planned on May 12. The market operator will instead work toward a start date for the release before June 30, after a second phase of testing with key participants is conducted on May 3.