BERLIN, April 6 (Reuters) - German Finance Minister Olaf Scholz welcomed on Tuesday a pledge by U.S. Treasury Secretary Janet Yellen to work on a global corporate minimum tax rate, adding that a deal among more than 140 countries could be possible by summer. “I’m in high spirits that with this corporate taxation initiative, we’ll manage to put an end to the worldwide race to the bottom in taxation,” Scholz said. He added that any deal must include new rules how to tax cross-border business by digital tech giants. Yellen said on Monday that she is working with G20 countries to agree on a global corporate minimum tax rate and pledged that restoring U.S. multilateral leadership would strengthen the global economy and advance U.S. interests. (Reporting by Michael Nienaber Editing by Madeline Chambers)