Manchester United and Bayern Munich have agreed upon a deal involving Bastian Schweinsteiger.
"Bastian wants to do something new at the end of his career," Rummenigge said at a news conference. "He asked that we meet his wishes.
"My colleagues at Manchester United have been in touch. We've reached an agreement over a transfer.
"It's regrettable because Bastian meant a great deal to the club. He achieved great things. We say goodbye on great terms."
Louis van Gaal managed Schweinsteiger at Bayern previously.