This follows an investigation into BTs pricing practices. This found BT to be charging third-party providers offering unmetered Internet access for call routing and management services that are no longer required.
Oftel has told BT to reduce its wholesale charges – and to backdate the reduction to June 2002.
When Oftel originally told BT to introduce a wholesale unmetered Internet access product, BT included a number of measures to support the new service. These were included in the charge to other operators.
Oftel's director general of telecommunications David Edmunds said: "BT has made significant improvements to its network since wholesale unmetered Internet access was first introduce over three years ago. At that time, BT included several mechanisms to route Internet calls through to the appropriate service provider and call management features to prevent its network being overloaded.
"BT's network can now process Internet call traffic without these additional measures. As a result, I have today ordered BT to reduce its wholesale unmetered Internet access prices," he said.
Oftel has also ordered BT to apply retrospective adjustments to its wholesale unmetered-access prices for the period August 1 2001 to May 31 2002. BT has been ordered to reduce its prices for the service by 6 per cent to cover this period.
Edmunds said: "The action ensures BT continues to recoup the cost of providing wholesale unmetered Internet access, and that UK customers continue to benefit from one of the most competitive ,dial-up markets in the world."
The investigation began after complaints from Cable and Wireless and Energis.
"I hope operators pass on these savings to their customers," said the regulator.