ScottishPower has joined forces with the voice, data, Internet and interactive services provider, Thus, to launch a new, fixed-line phone service offering domestic customers savings of more than one-third against BT's standard tariff.

This is the first of a series of potential telecoms joint ventures between ScottishPower and Thus, including the provision of Internet access. For the Telecoms Offer Thus will be responsible for network access, airtime and customer and technical services.

The Offer, promoted under the ScottishPower banner, marks a major entry into telecoms for the company and will be marketed to the 5.5 million households which are already supplied by ScottishPower for electricity, gas or water.

It builds on the success of ScottishPower's multi-utility approach which has established the company as a leading player in the UK electricity and gas supply markets. ScottishPower has won the greatest number of new electricity customers of any original electricity supplier in the UK and has gained nearly one million new energy customers with over 450,000 choosing to take combined gas and electricity packages.

ScottishPower will be offering savings of up to 35 per cent on local, national and international call charges to BT customers who have not yet taken advantage of the new, competitive marketplace for residential telephony.

Customers will also be able to benefit from a similar discount on calls to mobile phones and, as an introductory offer, a flat rate of 10p per minute for calls to five top international destinations - USA, France, Germany, Ireland and The Netherlands.

Charles Berry, ScottishPower's Executive Director, Customer Sales & Supply, said: "The experience of Thus in the telecoms sector coupled with ScottishPower's sales channels and extensive customer base means we are ideally-placed to exploit new opportunities in the domestic telecoms market".

William Allan, Chief Executive of Thus plc said: "We are extremely pleased to enable ScottishPower's customers to access our telecommunications services. This initiative complements our strategy to become a leading provider of telecommunication services UK-wide".