Olsen, who is due to leave on the second anniversary of the merger that created the company on July 15, was cleared of involvement in the affair in the report published last week.

He said it was true "some tensions" came up over the last period, and he thought it was in the best interests of everyone for him to move on.

"It is exactly two years after our start date and I am going to be leaving a group in great shape with clear targets in place," Olsen told reporters.

(Reporting by John Revill; Editing by Susan Fenton)