Complex sentence: AmCham EU's membership currently comprises around 140 companies, the majority are US multinational corporations but 25% of the members are Law Firms and Public Affairs consultancies, there are also a small number of international corporations who have demonstrated strong US business links.
Split into simpler sentences: AmCham EU's membership currently comprises around 150 companies, the majority of which are US multinational corporations. Although 25% of the members are law firms and public affairs consultancies, there are also a small number of international corporations who have demonstrated strong US business links.