ROME, May 21 (Reuters) - Italy, which holds the annual presidency of the G20, on Friday welcomed a proposal from U.S. Treasury Department for a global corporate tax of at least 15%. Washington on Thursday offered to accept a rate of at least 15% during international negotiations, significantly below its proposed 21% minimum for U.S. multinational firms. “The possibility of reaching a global and consensus-based solution is now concrete,” Italian Economy Minister Daniele Franco said in a statement. As president of the Group of 20 rich countries Italy will do “everything possible” to broker an agreement on a global minimum corporate taxation level at a G20 meeting in Venice in July, Franco added. (Reporting by Giuseppe Fonte, editing by Gavin Jones) Our Standards: The Thomson Reuters Trust Principles.