Over a quarter (27 percent) of big-company CEOs around the world are “extremely concerned” about over-regulation, according to a new survey from PricewaterhouseCoopers.

The CEOs said excessive regulation was the biggest threat to their business growth. And the majority felt that governments had done nothing to reduce the compliance burden they faced.

Asked to reflect on the financial crisis, the most frequently cited “lesson learned” by CEOs was that their approach to risk management had been poor. This was the case across all business sectors, not just financials.

Nearly all of the CEOs in the survey said they planned to change their company’s approach to risk management: 41 percent were planning “major changes,” 43 percent “some change.”

The survey was based on 1,198 interviews with CEOs in 52 countries. Interviews were conducted during the last quarter of 2009.