Eight of the 10 largest public companies in Minnesota now file their articles of incorporation other than in the State of Minnesota.

At UnitedHealth's annual meeting on June 1, about 92 percent of UnitedHealth shares supported a proposal to reincorporate the company under Delaware law.

On July 1 UnitedHealth Group became the latest Minnesota-based company to change its state of incorporation from the State of Minnesota to the State of Delaware.

The question may not be why is UnitedHealth changing its state of incorporation, but why they waited so long.

Many companies file their articles of incorporation in Delaware to take advantage of its General Corporation Law, the state's judicial system and long corporate case history. According to the State of Delaware website more than 1 million companies have made Delaware their legal home. That includes more than half of the approximately 12,000 publicly-traded companies in the United States and approximately 64 percent of the Fortune 500 companies.

Of Minnesota's 10 largest public companies only Target Corp. and Best Buy Co. Inc. are registered in the State of Minnesota.

U.S. Bancorp, General Mills, Supervalu, Ecolab, C.H. Robinson and even 3M Co. (whose corporate name let's not forget was originally Minnesota Mining and Manufacturing) and now UnitedHealth are all registered as Delaware companies. Medtronic PLC officially registered as an Irish company earlier this year.

Some of the charters and bylaws of UnitedHealth will change but according to UnitedHealth's SEC filing July 1 little else of consequence changes for the company. Each officer and director of UNH Minnesota now becomes an officer and director of UNH Delaware; shares, options and stock warrants of UNH Minnesota convert to equal shares, options, and stock warrants of UNH Delaware and the corporate name of UNH Delaware remains UnitedHealth Group Inc. and of course they remain headquartered in Minnetonka.