A mediator. A troubleshooter. Willing to tackle thorny issues. Former U.S. Sen. George J. Mitchell, Disney’s new chairman, has earned a reputation as an able diplomat and experienced voice at corporate helms.

The Walt Disney Co.’s board voted late Wednesday to split the roles of chairman and chief executive, hours after shareholders withheld 43 percent of their votes for CEO Michael Eisner’s re-election to the board. Disney directors also appointed Mitchell, a nine-year board member, as chairman.

Mitchell, 70, brokered a peace accord in Northern Ireland in 1998 and was the architect and namesake of a Middle East peace plan that won bipartisan and international support in 2001.

He also led an investigation into alleged bribes in Salt Lake City’s bid for the 2002 Olympics.

Since he left the Senate in 1994, Mitchell has also served on a wide range of corporate boards. The former senator from Maine is a director of FedEx Corp., Staples Inc. and Starwood Hotels & Resorts and has served on the boards at Xerox Corp., UnumProvident Corp., Casella Waste Systems Inc., and Unilever.

But it was his comments to former Lt. Col. Oliver North during the Iran-Contra hearing in the summer of 1987 that first catapulted him to national attention.

North’s passionate account of his arms-for-hostages activities in the name of God and country had produced an outpouring of emotional support.

“Please remember,” said Mitchell, then a junior senator, “… it is possible for an American to disagree with you on aid to the Contras and still love God and still love this country.”

Mitchell will likely need to call on his diplomatic experience in his new role. Shareholders withheld 24 percent of their votes from his re-election Wednesday – the second highest total after Eisner. And he has received acute criticism from many dissident shareholders over his cozy relationship to Eisner – a 20-year Disney veteran who may not yield power easily.

Born in Waterville, Maine, Mitchell worked as a U.S. Attorney and federal judge before joining Congress.

He is now a partner in the Washington law firm of Piper Rudnick.