The deal could be worth £13 million.

Tenon will make an initial payment of £10.4 million, of which £7.8 million will be paid in cash and loan notes, with the balance to be settled in shares. Further cash payments may be made over the next two years depending on the acquired business’ financial performance.

This is the third acquisition for Tenon in 30 days after it bought Bowmans Chartered Accountants and LWC Accountants last month.

Tenon’s chief executive Andy Raynor says: ‘This transaction is of major significance for Tenon. We have acquired a rapidly growing business in a specialist marketplace and entered the Yorkshire market at a very competitive level, significantly enhancing our offering across the North of England.’

Unity is based in Bolton, with offices in Wakefield, Hill, York and Middlesbrough. The business has 11 partners and 110 employees and comprises Unity Business Services, Unity Debt Solutions, Unity IFA and Jackson Jolliffe Cork. The group’s turnover for the year ending March 2007 was £8 million, and profits before partners’ remuneration amounted to £3.6 million.

AIM-listed Tenon has 1,500 staff operating through 31 offices in the UK. Its turnover last year was £123.6 million, with pre-tax profits of £4.2 million.