Ashton, who lost his job as England head coach despite leading the team to the 2007 World Cup final, has formally rejected the RFU's offer to become their national academy head coach.
Instead he is keen to work with the RFU in an advisory capacity. He said: "I have given full and careful consideration over the last two months to my future career plans.
"And I have decided to develop my own company delivering high level performance processes in all areas of sporting and business life.
"I now consider it the correct time to develop more varied challenges than just dealing with professional rugby.
"I am most grateful to the RFU for allowing me time and space to consider my future plans.
"I have decided not to accept the post offered to me by the RFU as head coach of the national academy, as this was a full-time post which would not have allowed me to develop my own business and pursue other interests.
"I am excited by the new opportunities in front of me and I am looking forward to providing a range of services to the RFU in the areas of elite coaching and coach development."