The bank said it would nominate four new directors to the board and that finance director Marco Suter had asked to step down from his job.

Investment banker Clive Standish will replace Suter on Sept. 1, the bank said.

The bank will also divide the group into three autonomous divisions: Global Wealth Management, its largest asset; the Investment Bank; and Global Asset Management, the bank said.

"Our review has clearly revealed the weaknesses associated with the integrated 'one firm' business model, UBS Chairman Peter Kurer said in a statement.

The new structure will add agility, "a spirit of transformation, clear accountability and transparency" to the bank's operations, Kurer said.