Stewart has 40 years of experience in the field of equipment leasing with extensive experience of working with leasing companies across Central and Eastern Europe, South America, Asia and Africa. He has established and managed leasing companies in transition economies, most notably in Poland. Since the end of 2003, Stewart has worked as a leasing and business consultant on projects in collaboration with the International Finance Corporation and the European Bank for Reconstruction and Development. In 2018 he established Agricultural Leasing Company Zambia Limited for the shareholders, KfW – the German Development Bank and Africa Agriculture Trade and Investment Facility to provide finance leases for small-scale farmers and agroprocessors.