The deal was first announced in February.

Third Financial is a provider of white label investment platforms and software.

Nucleus says the acquisition, for an undisclosed sum, will increase Nucleus Assets Under Advice to around £90bn.

The acquisition will also give Nucleus the ability to offer ‘adviser-as-a-platform’ services, enabling adviser firms to offer their own white label platform, a fast-growing segment of the market.

London-based Third Financial will continue to be led by existing chief executive Ian Partington.

Richard Rowney, CEO of Nucleus, said: “We’re pleased to have received regulatory approval and now look forward to welcoming the Third Financial team into our group. The acquisition extends and complements our existing enterprise and ‘adviser-as-a-platform’ proposition, enabling us to offer a full spectrum of platform models to advisers, consolidators and DFMs of all types.”

Nucleus Financial Platforms currently has over £80bn of assets under administration for 250,000 customers and owns a number of subsidiaries including James Hay, Nucleus and SIPP provider Curtis Banks, a recent acquisition.

Third Financial provides an investment platform and wealth management software. It serves discretionary wealth managers, multi-family offices and adviser consolidators.

Third Financial has seen growth in recent years with revenue increasing by more than 30% in 2023, it said. It has over 50 clients in the UK and a total of £6bn in assets under administration on its platform and a further £40bn of assets administered via its software system Tercero.

Nucleus says the acquisition will give it the ability to extend platform solutions to advisory firms of all sizes.

As well as an existing retail retirement platform and specialist SIPP and SSAS products, Nucleus will benefit from Third Financial’s proprietary technology, Nucleus says. It expects to offer its ‘adviser-as-a-platform’ proposition to larger adviser businesses who want to offer their own platform.