Ofcom has formally ruled that BT will not be allowed to increase its wholesale charges in order to plug a £3.8bn deficit in its pension fund, confirming the results of its initial consultation.
In making its decision, Ofcom said that it was important to create "an environment in which regulated firms, such as BT, and their wholesale customers are willing and able to invest" and said it wanted to maintain a consistent regulatory approach.
The comms regulator said it was concerned about the impact of allowing the changes on BT's competitors.
BT had asked Ofcom to change the way that it treats pension costs when setting regulated wholesale charges, but the regulator said it including deficit repair payments in regulated prices could "potentially lead to those prices being set at levels which do not accurately reflect the relevant underlying costs".
BT has said it hopes to lodge an appeal against the decision.