The Minnesota Vikings agreed Friday to add up to $26.4 million to build a new stadium, saying the additional funds will ensure the venue has "iconic" elements that will make it a marquee destination in downtown Minneapolis.

The Vikings announced the move as construction bids for the $975 million stadium came in higher than expected. To make up the shortfall, the team opted to contribute additional financing for the project, including $13.1 million it previously committed for contingencies.

All told, the Vikings' contribution could reach more than $518 million. The team said it was the only way to guarantee the stadium didn't lose distinctive features such as the giant louvered doors and critical technological elements, including giant scoreboards, ribbon boards, Wi-Fi access and HDTVs spread throughout the building, the team said.

"The choice was to cut something from the building, redesign it or step up the team's commitment, and that's what we decided to do," said Vikings spokesman Lester Bagley.

The "guaranteed maximum price" for the stadium is now $763 million — $25 million more than originally anticipated. If the Vikings' contingency funds aren't tapped, the money could revert to the team. But if contingency coffers are expended, the total cost of the stadium could top $1 billion.

"This additional commitment is to ensure several of the features that are so important to all users of stadium remain in this project," Vikings president Mark Wilf said in a statement.

Dipping back into public coffers — the state and city already are contributing $498 million — wasn't an option, said Michele Kelm-Helgen, the Minnesota Sports Facilities Authority's chairwoman.

In addition, $15 million of the overall stadium budget will be diverted to the construction fund — gameday revenue that was due to the Vikings for playing two seasons at TCF Bank Stadium at the University of Minnesota.

"We are acknowledging that the team has stepped up, allowing us to help keep the stadium's iconic design," Kelm-Helgen said.

The financial agreement approved by the authority on Friday now means construction on the new stadium can truly begin.

While a ceremonial groundbreaking is scheduled for Dec. 3, sharp-eyed observers may finally see evidence that a new stadium is planned on a spot now occupied by the Metrodome this Monday.

A fence will be erected on the Dome's northeastern flank, and construction cranes and rigs will be moved in to prepare the site for erection of the glassy behemoth, distinctive for its elongated prow and partly transparent roof — the largest of its kind in the world.

Also on Monday, the project's general contractor, Golden Valley-based Mortenson Construction, will place an order for heavy-duty steel beams from a firm in Luxembourg, with another 7,000 tons of steel to frame the building coming from domestic firms.

While excavation work will begin almost immediately, heavy construction — including deflation of the Dome's roof — can't commence until the Vikings finish their season Dec. 29 against the Detroit Lions. The entire project is expected to be completed by July 2016.

The project will employ about 7,500 workers, a welcome respite for recession-battered construction trades.

"It's a large signature project, and a lot of people will get back to work," said Dan Mc- Connell, business manager for the Minneapolis Building and Construction Trades Council. "There's a lot of buzz about it; people really want to be involved."

Going forward, if there are any cost overruns, Mortenson will be responsible for them. But the firm has extensive experience constructing sports stadiums, having built new homes for Minnesota's Twins, the Wild, the Timberwolves and the University of Minnesota football team.

John Wood, Mortenson senior vice president, said it's common for the general contractor for these projects to assume the risk. Unless there's a change in the design of the building, he doesn't anticipate any overruns, despite a tight construction schedule.

"We've done complex projects before," he said.