The boards have this morning said they have reached agreement on the terms of a recommended offer from Towry.
The companies said that their combination would create a "major player in the UK private wealth market, better able to meet the needs of, and offer a broader range of services to, clients".
Ashcourt Rowan, which provides wealth management, manages or has under influence over £5 billion in assets, of which £2.3 billion are on a discretionary or managed basis, from 16 offices in the UK with around 340 staff.
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Financial Planning firm Towry manages or advises on over £6 billion in assets and has around 800 employees serving clients from a national network of approximately 20 offices.
Ron Sandler, the chairman of Towry, said: "The combination of the Towry and Ashcourt Rowan businesses will bring an exciting opportunity to create one of the largest companies in the UK private wealth management sector.
"Our highly complementary business models will deliver significant client benefits, providing access to a broader range of services and investment solutions. Ashcourt Rowan has developed into a high quality business following a period of reorganisation and with a strong cultural fit, the combined entity will be well positioned to take advantage of further growth opportunities as the market continues to evolve."
Hugh Ward, the chairman of Ashcourt Rowan, said: "We are pleased that our recent discussions with Towry have been concluded positively and that the loyalty shown by our shareholders has been rewarded by this offer for Ashcourt Rowan.
"Our executive team has worked tirelessly to execute a recovery of Ashcourt Rowan's position since joining in late 2011 and effecting the placing in December 2011.
"The offer price of 275 pence per Ashcourt Rowan Share represents a fair price for the business, is a 4.7 times increase in the market capitalisation of the Ashcourt Rowan Group since 1 December 2011 and is testament to the dedication, passion and drive of all our staff.
"I believe that the combined entity will be well placed on completion to benefit from the growth dynamics of the wealth management industry over the coming years and provide an outstanding platform for key professionals in the sector."