The Carphone Warehouse is to invest up to £45m over the next three years as part of a major push into broadband and local loop unbundling (LLU).

Not just content with flogging mobile phones, and reselling fixed line and broadband services, Carphone has ambitions to become "the clear number one alternative telecoms provider".

Confirmation that the mobile retailer and telco is to invest in broadband follows hard on the heels of similar moves by satellite TV broadcaster Sky, Wanadoo and Plusnet, which have all recently announced their plans for LLU.

Carphone is to begin what it describes as a "major drive into UK broadband market" in 2006 with plans to install its kit in 1,000 BT exchanges over the next three years giving it access to two thirds of its customers.

The work will be carried out by Carphone's telco Opal, which it acquired in 2002.

"Our intention is to pursue a fully unbundled strategy, enabling us to take control of the switched voice line as well as the broadband connection," said Carphone in a statement.

"As always with our network infrastructure strategy, our level of financial commitment will be demand-driven, so that we will unbundle exchanges where we are confident of generating an attractive return on that investment through customer recruitment.

"Our intention is to pursue a fully unbundled strategy, enabling us to take control of the switched voice line as well as the broadband connection," it said.

Details of today's announcement came as Carphone published its interim results for the six months to October. Turnover was up 25 per cent at £1.29bn with pre-tax profit 35 per cent higher at £37m. ®