Tilney Bestinvest has completed its £600 million acquisition of Towry, which was first announced on 4 April.
The combined business now has over £20 billion in assets under management and administration, providing financial planning, investment management and advice, and an online service for direct investors through its Bestinvest brand.
It offers its services out of 30 regional offices across the UK.
Chief executive Peter Hall (pictured) said that following the completion, the group can now focus on developing its technology, client support and research.
'We are delighted to have completed this transformational deal. This brings together two individually successful businesses to create a truly market leading wealth management group that provides both highly skilled financial planning and award-winning investment management services right across the UK,' he said.
'While existing clients will see continuity in their advisers and the personalised service they receive, the greater scale the combination brings will enable us to support clients from a broader office network and offer a wider range of services to suit different needs.'
It was previously revealed that following the completion of the transaction, Towry chief executive Rob Devey would leave the business.
Tilney also said there will be no immediate changes to the branding of either business.