The deal, under Fairstone Downstream Buy-Out programme, adds 560 clients, five advisers and 11 support staff to Fairstone.
MT also brings gross fee income of £1.2m and £180m in Funds Under Management.
This latest deal is the sixth announced this year by Newcastle-based Fairstone which has acquired 43 adviser firms since 2011.
Under the terms of the deal Fairstone will steadily integrate MT over a two-year period before finally acquiring the business.
MT Financial Management is based in Spalding, Lincolnshire, and specialises in pension planning and investment management.
MT Financial Management principal Mark Hildred said: “Fairstone has a similar ethos to MT Financial Management, with a determination to service its clients to the highest possible standards. This ensures a seamless transition for our clients whilst offering an enhanced network of expertise.
“We are delighted to have partnered with Fairstone which will ensure the continuity of excellent service we have given our clients for many years and it enables us to retain all our existing advisers and staff.”
Fairstone chief executive Lee Hartley said: “We are pleased to welcome MT Financial Management into our Downstream Buy Out programme. Mark and his team bring a clear and efficient approach to their work, focussing on regular contact to build long-term client relationships.
“It is vital to have both a business and cultural fit with the companies who decide to join us and we are very pleased to have another company of this quality join Fairstone.
Fairstone is one of the largest Chartered Financial Planning firms in the UK and has annual fee income of over £65m.