Mike McDonald is the new joint owner of Costelow Engineering, the Bridgend mechanical contractor involved in a management buyout to be completed this week.
Retiring Terry Costelow, the man who put the T in 'T Costelow & Sons' is the founding father of the 35 year-old Bridgend business.
His son Simon Costelow has teamed up with Mike McDonald, who was the managing director of Elson until he left the company in September 2008.
After six months of working towards a management buyout, the buyout is expected to be completed on November 12.
Mike McDonald has spent nine years working for Baxi and 25 years at BSS, during which time he built up a good business relationship with Terry Costelow.
The Bridgend contracting firm has focused on mechanical design and installation. Having dropped the '& Sons' from the family business and formed a new name Costelow Engineering, Simon and Mike aim to make the most of the firm's renewables division which has grown rapidly in the last 12 months.
Costelow Engineering's new joint owner and commercial director, Mike McDonald said 'In three years renewables has grown from nothing to 10% of the firm's overall business. We expect to grow this to 20% of turnover by the end of 2009'.