Complex sentence: Given the business background of Marshall Plan's American leaders, the Americans' readiness to work with the Norwegian Labor government's ERP Council disappointed the conservative Norwegian business community, represented by the major business organizations, the Norges Industriforbund and the Norsk Arbeidsgiverforening.
Split into simpler sentences: Given the business background of the Marshall Plan's American leaders, their readiness to work with the Norwegian Labor government's ERP Council disappointed the conservative Norwegian business community. It was represented by the major business organizations, the Norges Industriforbund and the Norsk Arbeidsgiverforening.