Jim Curley, chief executive of Mice's international division said: "This is a very important acquisition. Gelardi's showbusiness contacts and expertise in the European and US markets, combined with Mice's international creative and production skills, will help establish Mice Group as a significant player in the world of theatrical production and corporate entertainment."
Gelardi was responsible for setting up Grosvenor Productions, the entertainment division of hotel and leisure group Forte, which was subsequently taken over by Granada.
Gelardi said: "Mice offers a strong client base and financial platform. We will offer an added service to Mice's corporate clients and together we hope to build a world leader in the entertainment business."
As well as providing creative expertise to corporate clients and private individuals, Mice Entertainment Services will offer an entertainment consultancy to the hotel and leisure industry.
Last month, Mice Group won the Queen's Award for Enterprise in the International Trade category.
Chairman Michael Curley said: "This is an important achievement for Mice Group in recognition of our rapid and continued expansion."