The Australian Competition & Consumer Commission (ACCC) said it was concerned about Telstra's registration of radio-communications sites in a low-band spectrum, which is likely to have hindered Optus, the local unit of Singapore's Singtel, from deploying its 5G network in Australia.

Telstra holds licences for parts of a low-band spectrum of 900 megahertz, which expire in June 2024. Such low-band spectrums have the ability to transmit over greater distances and are crucial for the roll out of a 5G network.

Both Telstra and Optus did not immediately respond to a Reuters request for comment.

In January, Telstra registered 315 sites in the 900 megahertz band spectrum after it became aware of Optus' intention to apply for early access to the Australian Communications and Media Authority (ACMA), the ACCC said.

So far, Telstra has de-registered 153 of these sites.

The regulator said that since the registration, Telstra has used only a limited number of these sites to deploy 3G services.

The telecom firm is now required to de-register sites it registered in January that would have prevented Optus from gaining early access to the spectrum.

"Telstra's undertaking will ensure Optus is not hindered from expanding its 5G rollout, giving more Australians access to a choice of 5G services in regional and metropolitan Australia," ACCC commissioner Liza Carver said.

"This is critical as 5G network coverage becomes an increasingly important factor in consumer choice in mobile phones and mobile plans."

ACCC said that an independent accredited person will be appointed to assess interference issues between the sites registered by Telstra in January and those necessary for Optus' 5G rollout.

(Reporting by Harish Sridharan in Bengaluru; Editing by Rashmi Aich)