Regional leaders have officially closed the door on a $700 million upgrade to the Edward Jones Dome, ushering in a new stage of negotiations with the St. Louis Rams.

This week, officials charged with running the Dome formally rejected — as long expected — the Rams’ proposal to overhaul the football stadium.

Kathleen “Kitty” Ratcliffe, president of the St. Louis Convention & Visitors Commission, sent a letter to the Rams to say the agency is “not in a position” to pay for a $700 million renovation.

In a separate letter, Jim Shrewsbury, chairman of the Regional Convention and Sports Complex Authority, said it would not be “prudent” to make the improvements recommended by arbitrators earlier this year.

“Basically, what we’re saying is we’re not going to be bound by that arbitration,” Shrewsbury said in an interview Friday. “It is not going to force us to upgrade the stadium.”

“We simply don’t have the money to do it.”

The end of arbitration, however, opens the door for a new round of negotiations.

Shrewsbury said Gov. Jay Nixon had asked to take the lead on this round — one nearly certain to include talk of a new stadium, rather than trying to upgrade the Dome. Area officials have already begun scouting for potential new sites.

Nixon’s office emailed a statement late Friday afternoon saying, “I look forward to hearing from the Rams about their long-term plans.”

The Sports Complex Authority owns the dome. The CVC operates it. Both bodies are run by representatives of the city, county and state, which combined to fund the Dome’s construction.