The deal, for an undisclosed sum, adds around 600 SIPPs to Curtis Banks' book and assets valued at around £180m.

It comes as Curtis Banks is preparing to launch a new SIPPs product in the near future.

Curtis Banks says that Hargreave Hale will continue to actively manage the invested assets but Curtis Banks will be responsible for the professional administration of the SIPPs.

It’s the 10th asset purchase by Curtis Banks since the company was founded in 2009.

Rupert Curtis, group chief executive of Curtis Banks, said: “This book of SIPPs from Hargreave Hale is a good fit for our business model and the clients will benefit from the high quality, service-led proposition that we provide.

“Having carefully taken the time to integrate Suffolk Life, our largest acquisition to date, we’re able to explore further opportunities to add scale and expand our offering to greater numbers of clients.”

Will Self, incoming Curtis Banks group chief executive from January, said: “Investing to add high quality assets is a core component of our future growth strategy. We also see great potential for improving organic growth, by better meeting the needs of advisers and their clients, and we’ll soon launch a new SIPP product to market. We’re targeting an increased rate of growth in 2019.”

Earlier this year Curtis Banks Group reported operating revenue up 47% to £43.6m and pre-tax profits up 31% to £5.9m in the 12 months to December 2017. At the time it also reported the total number of SIPPs it administers grew by 14% to 76,474 during 2017. Assets under administration increased 21% to £24.7bn during the year.