Olympus Corp. said Wednesday it paid $687 million in advisory fees for its acquisition of Gyrus Group PLC, almost double the ¥30 billion Olympus Chairman Tsuyoshi Kikukawa said the day before.

The fees paid between 2006 and 2010 in the purchase of Gyrus include a $443 million buyback of preferred shares, the company said in a statement. Kikukawa told the Nikkei newspaper Tuesday the total amount was about ¥30 billion.

Olympus issued the statement in response to media reports on a PricewaterhouseCoopers report commissioned by former President Michael C. Woodford, who was fired last week after questioning the size of the payment for the $2 billion purchase of Gyrus.