The Share Centre has reached an agreement to acquire the child trust fund clients of Witan, and a book of predominantly investment trust clients from JP Morgan.
The clients are investors who held their investment in a tax wrapper, either a child trust fund or an Isa or Sipp, directly with the fund providers rather than via a platform.
The JP Morgan client book involves 20,000 clients and £750m of assets potentially moving to the Share Centre, alongside a few hundred child trust fund clients at Witan, with the transfer expected to be completed by May.
The clients will be offered the chance to move to the Share Centre platform.
Ricchard Stone, chief executive of the Share Centre, said: "I’m delighted to announce the acquisition of these CTFs and it is a privilege to have been chosen by Witan.
"Encouraging consumers to get involved in investing from a young age is crucial as it means they can work towards creating a nest egg for future goals.
"The Share Centre is a pure execution-only stockbroker which provides substantial resources and guidance on our website to help personal investors but fundamentally our customers make their own investment decisions.
"We have an experienced team, are proud of the service we offer and look forward to providing customers of Witan with a secure home for their investments."
Hargreaves Lansdown announced earlier this week that it had also reached agreement to acquire a book of Isa clients from JP Morgan covering assets worth £765m.
It had previously acquired a book of clients from Witan, and has acquired a total of eight client books from asset managers in recent years.