Smith & Williamson, the appointed administrator, finalised the sale on 12 August 2019 following a period of marketing.
The deal also included the effective transfers of the Sipps and SSASs held via GPC’s trustee company, Guardian Pension Trustees, and GPC’s staff will be incorporated as well.
But the sum Hartley paid to acquire the Sipp provider was not disclosed.
Adam Stephens, the lead administrator, said: “We are pleased to confirm the sale of the business to Harley, which will provide continuity of service to GPC’s clients.
“We recognise that the insolvency of GPC may have been unsettling to clients.”
Hartley is a SSAS provider with over 35 years’ experience in the sector and started operating its Sipp business in 2001.
The firm is part of the Wilton Group and manages over £1bn ($1.21bn, €1.08bn) of clients’ assets.
The sale of a firm that has entered administration is one of the options available to administrators to avoid winding up the company, Stephens told International Adviser earlier this month.