The construction company that is advising the Minnesota Vikings on stadium plans in Ramsey County's Arden Hills said that state officials have it wrong and that there is enough time to build the project by 2015.

Minneapolis-based Mortenson Construction, which has built the last three major stadiums in the Twin Cities, said that should legislators approve the Arden Hills project by the end of this year, the stadium would be ready by the team's 2015 season. John Wood, a senior vice president for Mortenson, said in a letter released Tuesday that the schedule was aggressive but was "very adequate."

Two weeks ago, the Metropolitan Council and the Metropolitan Sports Facilities Commission concluded that the proposed $1.1 billion project in Arden Hills was "aggressive" and "unrealistic." The study was requested by Gov. Mark Dayton, who said he wants a special legislative session by Thanksgiving to reach a verdict on the long-running Vikings stadium issue and whether $650 million in public subsidies should help build the 65,000-seat facility.

Mortenson's letter came as the DFL governor, who has made the stadium a centerpiece of his agenda, said he will announce his own plan for the project by Nov. 7 and is open to building the project in Arden Hills or Minneapolis. The Vikings have said that Arden Hills is their preferred site and that the team and owner Zygi Wilf have committed at least $407 million to the project.

Reacting to the Mortenson letter, Dayton said Tuesday that "if [the Vikings] or their contractor or whomever can complete the project faster than the expected timetable, then more power to them." The governor added that he was expecting a letter from the team indicating the Vikings would pay for any unexpected cost overruns from delays, including environmental cleanup of the site, a former U.S. Army munitions plant.

For the project in Arden Hills to be completed by 2015, Wood said, the company needs "legislative authorization by the end of this year, [and] there would need to be an immediate start on design" in order to begin construction in late 2012, he said.

If that happens, he said, the company had "complete confidence" the 2015 construction target could be reached.

"We are certain that you are well aware of the unprecedented unemployment level that exists in the Minnesota construction industry," he added in a letter to the two regional agencies.

Mortenson Construction was the construction manager for Target Field, the new home of the Minnesota Twins; Xcel Energy Center in St. Paul, home of the Minnesota Wild, and TCF Bank Stadium, the new home of the University of Minnesota's football team. The Minneapolis-based company has also provided a cost analysis for remodeling the Metrodome, the downtown Minneapolis home of the Vikings since 1982.

A Met Council spokeswoman meanwhile disputed Wood's comments. "The time it will take to complete the complex land acquisition and environmental remediation requirements [in Arden Hills] is largely outside the control of Mortenson Construction," spokeswoman Meredith Salsbery said. "The timeline concerns reflected in the report center around land acquisition, site cleanup and regulation, and not the ability of the contractor to construct the actual stadium."

Wood said that Mortenson had also conducted an analysis of both remodeling the Metrodome and, earlier this year, building a Vikings stadium in Brooklyn Park or on the so-called Farmers Market site adjacent to Target Field in downtown Minneapolis. He said the company did the analysis as "complimentary services" provided to the Vikings.

Last winter, Ted Mondale, the Sports Facilities Commission's chairman, said that four potential sites for the Vikings stadium -- including the Farmers Market site -- had been vetted and deemed large enough to accommodate a modern football stadium.

Hennepin County Board Chairman Mike Opat said that county officials studied the Farmers Market site earlier this year and that Mortenson officials attended meetings to confirm that a stadium would fit on the property.

Staff writers Baird Helgeson and Kevin Duchschere contributed to this report. Mike Kaszuba • 651-222-1673