By Foo Yun Chee BRUSSELS (Reuters) -SAP, Europe's largest software maker, has offered concessions to address EU antitrust concerns related to its business practices, sources with direct knowledge of the matter said, as it seeks to stave off an investigation and potential fine. Germany's SAP is the world leader in enterprise resource planning (ERP) software used by companies to manage their finances, human resources, supply chains, sales and procurement. It has been on the European Commission's radar f ...