Ofcom may allow BT to increase the amount it charges rivals for using its network, according to preliminary conclusions published today by the industry watchdog.

"The evidence we have reviewed suggests that there is likely to be a case for some increases in the charges for the regulated access services," said Ofcom in its document entitled A New Pricing Framework for Openreach (PDF).

But the watchdog added that it considers BT's own price estimates to be on the high side.

"We do not currently believe that the increases need to be as significant as is implied by the projections provided by BT," Ofcom said.

The publication forms the first stage of a two-part consultation on BT Openreach's wholesale broadband pricing structure.

Exact pricing levels that Openreach should charge will be announced in a second review due to take place later this year.

The consultation will cover wholesale line rental in addition to local loop unbundling, where rivals such as Tiscali, TalkTalk and Orange are allowed to install equipment in BT's telephone exchanges to offer their own broadband services.

"We are encouraged by Ofcom's approach to the review, both the proposed timescales and its intention to open all the key issues to consultation," BT said in a statement.

The telco added that current fixed prices "are not sustainable indefinitely" .