Dalrymple Bay Infrastructure, which owns Queensland’s biggest coal port, will have to tell coal miners how it calculates fees to use its terminal and allow arbitration of disputes from July following a ruling by Queensland regulators.

The Queensland Competition Authority has rejected DBI’s so-called draft access undertaking proposal, which governs how it runs the Dalrymple Bay coal terminal south of Mackay, arguing it did not sufficiently constrain the company’s “market power” and would not be in the public interest.