PARIS, May 21 (Reuters) - The latest U.S. proposal in international talks for a global minimum corporate tax rate are a basis for compromise, French Finance Minister Bruno Le Maire said on Friday as he arrived for talks with euro zone counterparts in Lisbon. The U.S. Treasury Department on Thursday offered to accept a global minimum corporate tax of at least 15%, a rate significantly below its proposed 21% minimum for U.S. multinationals. Reporting by Leigh Thomas Editing by David Goodman Our Standards: The Thomson Reuters Trust Principles.