Telecoms body Ofcom has announced it has received complaints from vendors Thus and Gamma Telecom alleging BT of abusively squeezing margins in selling wholesale end-to-end voice calls to the channel.

Ofcom opened the case today with Gamma and Thus claiming BT has contravened Chapter II of the 1998 Competition Act and Article 82 of the EC Treaty, which relates to abuse of a dominant position. It is alleged that, since 2005, BT's pricing of wholesale end-to-end voice calls for resellers has been below cost and aimed at eliminating or weakening competition.

Vendor Cable & Wireless, which has been wrangling to buy out Thus for more than two months, has also announced its support for Thus' complaints. The investigation is now open and Ofcom will try and ascertain whether or not BT has abused a dominant position under UK and/or EC competition law.

Richard Bligh, Gamma's group marketing director, said: "We are alleging that BT has operated unfairly. What we are trying to do,is ensure a level playing field and a healthy competitive industry. We do think we are acting in the best interests of the channel and the end customer."