He will be replaced by Peter Coleman who currently works as commercial director and joined the firm in March 2011.
Mr Coleman's main role will be making the final preparations for RDR transition at the end of the year and identifying further opportunities to grow the business.
To achieve this he will be working with risk and compliance director James McCourt.
Patrick Gale, Aegon executive chairman of distribution, said: "I would like to thank Jim for his significant contribution to Positive Solutions over the last four and a half years and I wish him well in his future career.
"Positive Solutions must now focus on delivering profitable growth in the run up to RDR and beyond. Peter and James's knowledge of the business and their track record make them an ideal team to lead the firm to future success."
Mr Coleman said: "Positive Solutions has the right strategy to be one of the winners post-RDR.
"I'm delighted to be given the opportunity to lead Positive Solutions at such an important time for the firm and the industry."