The news that World Online has pulled out of the trials follows similar announcements last week by Thus, formerly Scottish Telecom, and Kingston Communications.
Andy Frost, director of products and services at World Online, cited uncertainty about the cost of participation in the trial as a reason for backing out, and claimed that guidance by Oftel was unclear.
Justin Fielder, local loop unbundling (LLU) manager at competitor Easynet, blamed the ease with which companies could pull out of the trials for the withdrawals. Under the terms of the trials, operators were not locked in to a making a serious commitment towards the unbundling process.
He believes that several operators signed up with no intention of going forward with unbundling and sees the latest withdrawals as "a bit of a reality check". Fielder said that latest withdrawals are "very frustrating" and had caused other operators a "massive waste of resources" in spending on design work.
He added that he had been surprised at the number of operators signing up to LLU in the first place. Pitching unbundled lines to residential customers made no sense unless operators had deep pockets and took a long-term view.
Speaking previously, Eddie Murphy, senior analyst at Analysys, said the LLU process in the UK was "hideously complicated". He said that the whole issue of access to exchanges and collocation had been problematic and expected the operators involved to come down to a small number of serious players.