NTL is outsourcing or axing 6,000 jobs by the end of 2007 as it completes the integration of Telewest, which it acquired this year.
NTL acquired Telewest for £3.4bn and is now looking to deliver cost savings of £250m through outsourcing and reducing operational duplications.
As part of the restructuring plan, around 1,500 call centre jobs in Swansea and Liverpool will be outsourced to IBM. A small number of posts in Teeside will also move to the outsourced operation.
A further 4,500 jobs will be axed as a result of the outsourcing process through both natural wastage and voluntary redundancy, said NTL.
The firm admitted there would be some compulsory redundancies. It also plans to slash the number of temporary workers it employs.
The heavily indebted NTL posted an operating profit of £4m for the first three months of the year. NTL has debts of £5.4bn.
NTL intends re-branding itself under the Virgin name, following its recent acquisition of Virgin Mobile.