If the Vikings must leave the Metrodome for an Arden Hills stadium to keep the team in Minnesota, then city officials are all for it, Minneapolis Mayor R.T. Rybak insisted Thursday.

They just don't think the money they've put into the Dome for 30 years should be going there too.

Rybak said that he fully supports the Vikings' efforts to move to Arden Hills, despite seeking a chunk of proceeds from the Dome's sale that might otherwise go to the new stadium.

"For six months I've been supportive and have said nothing negative about the Ramsey proposal," he said.

"But we got wind of what we understood to be a new wrinkle in private negotiations that we haven't been part of, that would have been a raid on dollars generated by people in this city."

On Monday, Rybak and City Council President Barbara Johnson sent a letter to Gov. Mark Dayton seeking a $30.5 million repayment of money that they said the city had spent over the years on the Dome, should the Vikings head east to Arden Hills and the 30-year-old stadium be sold.

Rybak said he spoke with Dayton on Thursday and assured him that Minneapolis continued to back the Arden Hills effort. In answer to reporters' questions, Dayton said at an afternoon news conference that he had read the city's letter.

"I don't dispute it," Dayton said, adding that he had not yet reviewed it with his stadium experts.

The governor repeated earlier statements that the new stadium's $1.1 billion price tag "may reach upward as things unfold." The possible repayment to Minneapolis, he said, is just "one of those pieces."

Surprise at Capitol, Winter Park

But the timing of the Minneapolis request surprised both the Vikings and Rep. Morrie Lanning, R-Moorhead, one of the stadium bill's key sponsors.

Lanning said that stadium advocates have known for a long time that proceeds from the Dome's sale were in play.

"I would have thought we would have had a letter like this a long time ago," he said.

Lester Bagley, the Vikings vice president for public affairs and stadium development, said that in 2006 Minneapolis officials supported a state law that built Target Field for the Minnesota Twins and directed most of the revenues from the Dome's sale to a "football stadium account."

At the time, the Vikings were in discussions to build a new home in Anoka County, but Bagley said the underlying aim remained.

"The intention and direction was when the stadium gets cashed out, the proceeds would go to help fund a new football stadium," Bagley said.

Seeking 'more sunshine'

Despite Rybak's insistence that the letter was not meant to hobble the Arden Hills plan, it added yet another twist to the expanding stadium debate.

Next week, the Ramsey County Charter Commission will hear testimony on whether residents should vote on the proposed sales tax to help fund the Arden Hills stadium.

A report from the Metropolitan Council and Metropolitan Sports Facilities Commission on the proposed site is due in three weeks, and a special legislative session in the fall to consider a stadium bill remains a possibility.

In the letter to Dayton, Rybak and Johnson said that Minneapolis deserved to be reimbursed for its "quantifiable contributions" to the Dome since 1979.

The repayment would include $5 million that the 2006 state law says would go to Minneapolis from the Stadium Commission if the Dome were sold. The law says that proceeds from the Dome's sale would go into a "football stadium account" to pay debt service on bonds for a new Vikings stadium -- save for $5 million to Hennepin County to offset ballpark improvements.

Johnson said that Minneapolis officials want "more sunshine and to make clear [that] when you're using taxpayer dollars to move a business from one city to another," there should be compensation.

The Star Tribune owns five blocks near the Dome that could be involved in a stadium deal. In 2007 the Vikings struck a tentative $45 million deal for that property but withdrew, citing turmoil in credit markets.

The Ramsey County deal envisions a $407 million contribution from the Vikings, $300 million from the state and $350 million from the county raised through a half-cent increase on the county sales tax.

At his news conference Thursday, Dayton said the end deal for the stadium is not yet clear. "I can't ask people to support a deal when I can't say specifically what it is," he said.

"Some questions have been answered. Many have not. But I think a lot of it will be in clear focus on Oct. 15," he said, when the Met Council and Stadium Commission report on the Arden Hills site is slated to come out.

Until then, he said, the stadium matter is essentially on hold.

Staff writers Mike Kaszuba and Rachel Stassen-Berger contributed to this story. kduchschere@startribune.com • 612-673-4455 raolson@startribune.com • 651-925-5035 Twitter: @rochelleolson