CityFibre has urged Ofcom to encourage alternative fibre providers to boost fibre infrastructure across the UK.
Last week, BT agreed to the watchdog's demand for its infrastructure subsidiary Openreach to become a distinct and legally separate company.
However, CityFibre is not convinced that governance changes at Openreach will lead to it adopting a fundamentally different approach in the future.
Mark Collins, Director of Strategy and Policy at the firm, commented: "Whilst it is welcome that these time-consuming negotiations seem to be at an end, there is nothing in this announcement to suggest Openreach will now start to build the fibre infrastructure this country needs."
He has therefore insisted that Ofcom should shift its focus to encouraging other providers to "do the things Openreach can't or won't do - whatever its legal status".
"The real story here is the UK’s shocking fibre gap," he continued.
However, Mr Collins said CityFibre is well-placed to meet this challenge and achieve Ofcom's goal of reducing Britain's dependence on Openreach.
He added that the substantial government funding for fibre announced in last week's Budget will help CityFibre accelerate its own full fibre rollout programme.
Chancellor of the Exchequer Philip Hammond confirmed £200 million will go towards speeding up the delivery of full-fibre broadband networks.
As part of this effort, the government will offer full-fibre broadband connection vouchers for businesses, to boost the take-up of services where new networks are built through the programme.
Public sector assets, such as existing ducts, will also be opened up to reduce the cost of deploying fibre technology, while public sector buildings, such as schools and hospitals, will be directly connected.