Economic development of the industrial countries is characterized by an increasing share of services in Gross Domestic Product (GDP) and in employment. Among the different services, communication and transport are fully or mainly producer-orientated. The growing integration of services with productive activities is an important factor in the growth of producer service industries. The sectoral classification laid down by OECD contains both producer and consumer services within individual sectors. Traditionally financial services are regarded as including banking, insurance as well as real estate services. In most European countries statistical coverage of the service sector and its individual sub-division is in its infancy. Among business services, information technology services have expanded fastest and the economies of the industrial nations have thus been substantially transformed. The growth differential of labour productivity between service and goods production gives rise to the growing employment share of the service sectors.