Oftel intervened to get local loop unbundling - the process by which BT allocates space in its networks to rival operators so they can supply high-speed Internet access - back on track.
Increased competition for the local loop should help to improve the broadband Internet services available to companies hoping to take advantage of the Web.
Nine of the original 27 operators, including Thus and Cable & Wireless, have withdrawn from the local loop process.
Under the new terms and conditions, operators and BT must agree levels of service to ensure that BT provides operators with reasonable service on a non-discriminatory basis.
In the case of a dispute about the provision of local loop unbundling, operators will be able to refer to an independent expert under a new dispute resolution procedure.
Operators will also be allowed to trade space with each other if they order too much, rather than having to give it back to BT.
Derek Nicholas, of the Communications Managers Association, said, "It is a step in the right direction but it is clear that continued regulatory intervention will be necessary to ensure local loop unbundling continues to make progress. This is somewhat indicative of the whole process."