ST. LOUIS (AP) — An attorney for the agency that runs the home of the St. Louis Rams says it is unlikely it will implement the team's plan to upgrade the Edward Jones Dome.

Already, there is speculation about a new stadium.

Arbitrators ruled last week in favor of the team's plan for upgrading the dome to "top-tier" status as required by the lease agreement with the dome owner, the St. Louis Convention and Visitors Commission. The CVC had proposed $124 million in renovations. The Rams didn't put a price tag on their plan but CVC and city officials believe it would cost $700 million to $800 million.

The CVC has 30 days from the date of the ruling on Friday to decide if it will try to implement the Rams' plan, though attorney Greg Smith said in a statement that step was "unlikely."

Smith and a spokesman for the Rams did not return messages seeking comment Monday. But Jeff Rainford, chief of staff for St. Louis Mayor Francis Slay, said there was almost no chance the CVC will even try to garner public support for spending hundreds of millions of taxpayer dollars to improve the dome.

"It will clearly be the job of the St. Louis civic community to keep the Rams in St. Louis, but with the least amount of public subsidy possible," Rainford said.

Unless the CVC implements the plan approved by arbitrators, the Rams' lease of the dome becomes year-to-year starting in March 2015. That creates the possibility that the Rams could leave St. Louis.

Rams management has said the team wants to stay, and NFL Commissioner Roger Goodell said last week he was hopeful the stadium situation would be resolved. But the Rams have also been adamant that the dome is inferior to most NFL stadiums.

The CVC a year ago proposed improvements that included better amenities and a massive new scoreboard. It would have required to Rams to pay for $64 million of the $124 million cost. Voter approval in the city and county would have been required for the rest.

The Rams countered with a much more elaborate plan calling for a new roof with a sliding panel, replacing much of the brick exterior with a glass front, even re-routing a nearby street. The Rams did not say how it would be funded.

Three members of the American Arbitration Association — retired Colorado judge Federico C. Alvarez of Denver, former judge David Blair of Sioux City, Iowa, and labor attorney Sinclair Kossoff of Chicago — found problems with the dome that indicated a need for a massive overhaul. Among other things, they noted it is among the smallest stadiums in the NFL, and wrote the dome "lacks openness, light and air" that would require installation of an expensive retractable roof to resolve.

Some in St. Louis believe the answer is a new stadium. The St. Louis Post-Dispatch cited three possible locations: In Fenton, at the site of a former Chrysler plant; near Interstate 70 in Maryland Heights, not far from the Rams' practice and office complex; and in the Bottle District north of downtown St. Louis, an area not far from the dome.

Fenton Mayor Dennis Hancock said no one from the Rams has approached him.

"That being said, if somebody wants to build a stadium on that site I think it's something we would be interested in working with them on and try to create something that would be positive for the region and the city of Fenton," Hancock said.

The mayor in Maryland Heights did not return a message left Monday morning. Rainford and Mike Jones, senior policy adviser for St. Louis County executive Charlie Dooley, declined to speculate about a new stadium.

But Jones said, "The real question becomes what happens next? I don't think that discussion has even begun."

Any plans for public funding to help build the stadium would likely go to a vote of residents of St. Louis city and county.

Taxpayers are already footing the bill for the existing dome, which cost more than $300 million when it was constructed in the mid-1990s. However, repayment for the 30-year bonds that financed it will total $720 million. The state of Missouri pays $12 million annually toward that debt; the city and St. Louis County pay $6 million each.