Stephen worked for BAE Systems from 1992 to 2006 in financial and general management roles. He was Group Director of Financial Control and Accountancy at the time of the merger with Marconi Electronic Systems. From 2002 to 2006, he was the Group Managing Director of International Partnerships, responsible for a portfolio of European defence systems joint ventures. These included MBDA of which he was Chairman. Since 2008 Stephen has been Chairman of the Nuclear Decommissioning Authority, responsible for the decommissioning of the UK’s first generation civil nuclear facilities. He is also Chair of the Board of the University of Cumbria.