Customer should be wary of signing to up unbundled providers, a broadband comparision site has warned.

The practice of local loop unbundling (LLU) is perceived by many as a gateway to cheaper broadband

However, according to Michael Phillips or BroadbandChoices.co.uk, customers signing up to unbundled provider could, in fact, be left facing "expensive consequences".

He explained: "It costs somewhere in the region of £35,000 to unbundle a single exchange. So providers are keen to add as many customers as possible to their unbundled networks - sometimes moving them over without the customer even realising."

"But because LLU uses a different type of technology to traditional ADSL connections, customers could face a break in their broadband connection and have difficulty in returning to the BT network if they're not happy with the service.

"They may even have to pay BT £124.99 to have their phone line reconnected if both their broadband and home phone had been moved to an unbundled network," added Mr Phillips.

Figures from BT show that there around 2.5 million customers using LLU services in the UK and 1,000 exchanges.