Alliance Trust has sold part of its savings platform business with £3 billion of assets to a specialist in self-invested personal pensions (Sipps).

Bristol-based Curtis Banks will take over 6000 Sipps from Dundee-based Alliance Trust by the end of the year.

Alliance said: "As part of the acquisition, Curtis Banks are retaining all affected staff, in both Dundee and London, to ensure continuity of service."

Curtis Banks has been involved with Sipps since 1995 and small self-administered schemes since 1977. The acquisition will give it a leading position in the Sipp market. Only the Full Sipp, not the Select Sipp, offered by ATS is affected.

Alliance Trust came under heavy fire last year, in the campaign by activist shareholder Laxey Partners, for losses sustained by Alliance Trust Savings in recent years totalling more than £30m. But chief executive Katherine Garrett-Cox has recently pledged the ATS business will be in profit by the end of the year

Patrick Mill, managing director at ATS, said: "By selling our SSAS and full Sipp books this year we can focus entirely on the growth of our platform business.

"We anticipate significant growth opportunities in the platform market over the next few years as our proposition is ideally placed to benefit from the transparency that will be brought in as a part of the FSA's retail distribution review."

Rupert Curtis, managing director of Curtis Banks, said: "This is a quality book of business and our retention of staff and processes will ensure 'business as usual' while providing a strong foundation for future development."