RSR, which has £108 million of funds under management and more than 100 active clients, is the third to be snapped up by Bellpenny in Glasgow since last year. It comes after Bellpenny, backed by US wealth management giant Oaktree, acquired KM Financial Advisers and MGW in the city in the second half of 2013.
The RSR deal is Bellpenny's 22nd acquisition since being set up in October 2012 to take advantage of changes brought by the Retail Distribution Review (RDR).
Bellpenny had £2.5 billion under management prior to the RSR acquisition.
A statement on the RSR website notes the company has ceased trading under its current name and has been fully integrated into its new owner.
One of the co-owners, Paul Angell, is moving across to Bellpenny with the company's 12 staff, and the RSR office in Glasgow will be retained, although it will be rebranded.
However Tony Ross, the firm's other owner, is not joining Bellpenny. A spokesman for Bellpenny said "it's very much a seamless integration" for RSR clients and staff.
The RSR owners said in a statement: "It's easy to see why Bellpenny is proving to be the acquirer of choice for so many IFA businesses, both north and south of the Border. They've taken full advantage of the opportunity to build a post-RDR (Retail Distribution Review) business from first principles, with the client right at its heart.
"And from an IFA owner's perspective, the whole process of selling the business, from initial contract through to signing on the dotted line, is a well-oiled machine."
Bellpenny chief executive Kevin Ronaldson said the firm's hat-trick of deals in Glasgow shows "we're building a formidable presence in the city and surrounding area".