Minnesota companies less likely to split the chairman and CEO roles.

Minnesota's Fortune 500 companies are slightly less likely to split the chairman and CEO roles than their national counterparts.

Willis Towers Watson, the global advisory and risk management company, recently published an article that shows for the first time more than half the U.S. companies in the Fortune 500, 52 percent, separate the roles of chairman and CEO.

There are 17 Minnesota companies in the Fortune 500. At nine of them the same man holds the chairman and CEO roles.

Among Minnesota's Fortune 500 companies that don't currently split the chairman and CEO roles are Target, Best Buy, 3M Co., U.S. Bancorp, General Mills, Ecolab Inc., C.H. Robinson Worldwide, Ameriprise Financial, and Xcel Energy.

U.S. Bancorp recently announced that chairman and CEO Richard Davis would surrender his CEO role at their next annual meeting. He'll remain chairman and Andy Cecere, currently the chief operating officer, will become the CEO.

The 58 year-old Davis became CEO of U.S. Bancorp in Dec. 2006 and was named chairman and CEO in Dec. 2007. U.S. Bancorp's most recent annual proxy statement filed in March states that "Our Board of Directors has adopted a flexible policy regarding the issue of whether the positions of Chairman and CEO should be separate or combined."

The Fortune 500 list ranks public companies, cooperatives and certain nonprofit organizations on total revenue.

The trend for separate roles has been building for over a decade according to the Willis Towers Watson report. In 2006 just 32 percent of Fortune 500 companies split the roles.

Splitting the roles is a good governance issue that shareholders, activist investors and proxy advisory firms have increasing advocated for. Those advocating for the split generally argue that an independent board chair can hold management to greater accountability and set a pro-shareholder agenda.

Others insist that a CEO can handle the additional role of chairman of the board because they have greater insight into the operations of the company and can present a stronger link between management and the board.

The Dodd Frank regulations that were passed in 2010 included a provision that required companies to disclose the reasons why they have adopted their leadership structure.

Many companies don't have a hard and fast rule on splitting the roles. The Willis Towers Watson research showed that "37 percent of the current stand-alone board chairs previously served as CEO of the same company."

Supervalu currently has a non-executive chairman of the board in Gerald Storch. But their proxy states "The Board believes that it is not in the best interest of the company or our stockholders to have an inflexible rule regarding whether the offices of chairman and CEO must be separate." That statement opens the door for the roles to be unified at some point in the future.

At Hormel and Mosaic the roles are currently split but in recent years they had one person occupy both roles. In each of their proxy statement they make room for a "flexible approach" or "retains the right to exercise its discretion in combining or separating the offices of chairman and CEO."

Even when a company combines the role of chairman and CEO they'll often appoint a lead independent director who can also help set the agenda of the board.

Last year Best Buy CEO Hubert Joly assumed the role of chairman after several years of reporting to independent chairman Hatim Tyabji. But they did name board member Russell Fradin as a Lead Independent Director.