The communications regulator Ofcom has notified the European Commission that it is looking to impose caps on how much infrastructure provider BT Openreach can charge other operators for access to its network.
The proposal is subject to the European Commission's approval through a new consultation process.
The move could benefit other operators such as TalkTalk and Sky, because they would pay less to use BT's infrastructure to offer broadband to their customers.
In response to Ofcom's move, BT said that it could appeal any decision to allow Ofcom to impose price caps.
"While the prices are within the range outlined by Ofcom in November, we disagree with some of the underlying assumptions that they have used to determine these charge controls.
"Our primary concern throughout this process is to ensure that we are able to achieve a fair rate of return in order to continue our investment in the future of the UK's communications infrastructure.
"We will consider all options available to us, including appealing, after Ofcom confirms its final decisions," BT said.
Under Ofcom's proposal, a fully unbundled line to a property where an operator takes over the lines to provide broadband and telephone services would be charged at £87.41 for 2012/13. The proposal would see the charges reduced further in 2013/14. Openreach currently charges £91.50.
A shared unbundled line to a property, where a communications provider uses a proportion of the line only for the provision of broadband is currently charged at £14.70 to other operators. The provisional price would be £11.92 for 2012/13 with a further reduction the following year.
Finally, wholesale line rental, which is used by communication providers to offer telephone services to consumers using lines rented from BT, would drop from £103.68 per year to £93.81 for 2012/13 and would drop again the following year.
Ofcom said that it expects to publish a final decision on the proposed charges in early March.