DeVere Group has received regulatory approval to buy adviser business WPS Advisory Limited.
WPS Advisory, which used to trade as Priscum Direct, will become part of DeVere's UK subsidiary, UK Workplace Solutions.
Nigel Green, DeVere Group founder and chief executive, said: "We’re understandably thrilled with this development.
"This latest group acquisition underscores DeVere Group’s ongoing commitment to the UK and to investing in financial services firms that truly reflect a changing market, regulatory and legislative landscapes in Britain.
"I personally look forward to helping this forward-thinking, and game-changing company become successful in reaching even more people who are facing tough retirement choices."
Workplace Solutions was founded, with investment from DeVere Group, in January 2015 to provide retirement advice.
Simon Chrystal, managing director of Workplace Solutions, said: "Receiving the approval notice was the final piece in a jigsaw which will allow us to enhance our position, with WPS Advisory Limited becoming our single brand, as a leading provider of access to high quality, affordable, financial advice – primarily via the workplace."
Earlier this week DeVere UK reported increased losses of £1.2m because it faced "significant costs" associated with an ongoing investigation by the Financial Conduct Authority.
Last year DeVere UK agreed to "immediately cease" providing third party companies with transfer value analysis reports after intervention by the FCA.
The international advice firm was also subject to a section 166 notice, which means an independent "skilled person" would review the firm’s activities, paid for by DeVere.