Clyde & Co said it has advised Windsor and Windsor's non-executive directors on the recommended cash offer for the international insurance broker by its senior management and employees.
The offer price was 52.5 pence per share, so valuing the company at approximately £33.7m.
Windsor was acquired by Ostrakon Capital, a specially formed company 78% owned by 68 of Windsor's senior management and employees.
The remaining 22% of Ostrakon is held by Hutton Collins Capital Partners II LP, which also provided debt financing.
Further debt financing was provided by KBC Bank NV. The buy-out was effected by means of a scheme of arrangement under section 425 of the Companies Act 1985.
The Clyde & Co team was led by Gary Thorpe and Chris Duffy, partners in Clyde & Co's London corporate group, who were assisted by Nicholas Foss-Pedersen and Iain Macdonald.
Thorpe said: "The high level of employee participation in the buy out was unusual. This gave rise to a number of interesting procedural issues in relation to the scheme of arrangement by which the buy-out was effected. I wish the Windsor Group and its participating employees every success as a private company."
Keith Chapman, Windsor's senior non-executive director, added: "I am delighted that the management have completed their buyout. The future of Windsor's staff and clients is best served by the ownership of Windsor being by the management, and I wish them all the very best for the future."
