Clark was previously Managing Director of Siemens Building Technologies a position he held since September 2005. Before joining Siemens Building Technologies Clark was Managing Director of Siemens Power Generation.

Following the acquisition of Siemens Westinghouse in 1997, Parsons Works in Newcastle became part of the Worldwide Manufacturing and Engineering Network, supplying products for new apparatus and modern upgrades of existing plant as well as continuing with the service and upgrades of the existing Parsons fleet.

Clark joined ‘Parsons’ in 1982 and held a number of positions in procurement, project management and engineering management, before taking up his first general management position in 1996, the role he was undertaking when Siemens acquired the company. Quickly becoming integrated into the Siemens organisation, Clark took an active role within the manufacturing integration team when Siemens acquired Westinghouse Power Corporation of USA including secondment to Mülheim, Germany, where he was responsible for the co-ordination of the global Siemens Power Generation steam turbine manufacturing network, with production in six countries.

During his time in charge at Siemens Power Generation, Clark managed three acquisitions, two disposals and three restructuring programmes, including converting the manufacturing plant at Newcastle into a service facility.