DENVER — A transaction combining the flour milling assets of Cargill, ConAgra Mills and CHS, Inc. has been completed, creating Ardent Mills, the largest flour milling company in the United States.

The joint venture will operate 40 flour mills, three bakery mix facilities and a specialty bakery.

First announced in March 2013, antitrust objections necessitated the divestiture of four flour mills by the founding companies. The sale of the four mills, to Miller Milling Inc., was completed May 27, two days before the Ardent transaction closed.

Pride in the milestone was voiced by Dan Dye, the chief executive officer of Ardent. Previously, Mr. Dye had served as president of Horizon Milling, a Cargill-CHS joint venture.

“This is a proud day for our employees and customers who have supported Ardent Mills during every step in this process as we begin a new era in grain,” Mr. Dye said. “Today is about many parts coming together to make a new and stronger whole. It’s about a collective strength, history and ability to deliver quality and nutritious ingredients and carry that legacy into the future.”

Ardent headquarters will be in downtown Denver, though the company is not expected to have a presence there until later in 2014. Still, the formal establishment of the company was cause for effusive celebration in the state of Colorado.

“Landing Ardent Mills is a little like winning the Super Bowl — or at least the Flour Bowl — especially for rural communities,” said Governor John Hickenlooper. “We are thrilled and honored that Ardent Mills has made this investment in our state. We are at the ready to support their team, and we have every confidence Ardent Mills will become the most innovative and successful milling operation in the country.”

Also commenting on the nation’s newest flour milling company was James A. McCarthy, president of the North American Millers’ Association.

“The North American Millers’ Association welcomes Ardent Mills and the innovations it will contribute to our industry,” he said. “This new company represents the ongoing strength of the U.S. milling industry and the popularity of milled flour products.”

Bill Stoufer most recently was president of ConAgra Mills. He is the chief operating officer and chief integration officer for Ardent.

“There is an excitement and energy among our employees to deliver quality ingredients rooted in sustainability, health and wellness, and aligned with the latest food trends,” he said. “Ardent Mills will be a trusted partner for our customers, and we will always challenge ourselves to provide the best to our consumers and communities through innovative and nutritious grain-based solutions.”