PEXA, the Commonwealth Bank-backed property settlement exchange, could be forced to open its platform to competitors after regulators in NSW and Queensland wrote to the industry and said they would proceed with attempts to end its quasi-monopoly.

The ASX-listed group, which has almost the entirety of the transfer markets in most states, and others in the sector had been given a deadline of December next year to make sure various platforms worked with one another. But last month the sector regulator abruptly decided it did not have the power to force it to do so, ending the process.