BLOOMINGTON - Mike Nelson probably will leave his post as co-owner of the management group that operates the city-owned U.S. Cellular Coliseum. | Interactive graphic: Coliseum finances, attendance | Thunder close to filling front-office post | Extreme schedule, results

Bill Mueller, attorney for Central Illinois Arena Management, had no comment Thursday about business partner John Butler buying out Nelson's share of the management group. Attempts to contact Butler and Nelson were unsuccessful.

"I have heard some rumors that they have been talking about restructuring the management team, but I don't know how far that has progressed," said Bloomington Mayor Steve Stockton.

A 10-year contract for CIAM to operate the Coliseum was approved by the Bloomington City Council in October 2005. As part of that agreement, Nelson and Butler each earn an annual salary of about $87,000 and CIAM receives 4 percent of the total revenue. In 2008, that fee totaled about $140,000.

How any CIAM ownership changes would affect the agreement with the city are not yet known.

"Just off the cuff, I don't think it will change anything because the city's contract is with CIAM and not the individuals," Stockton said.

If there is a change, Stockton said the City Council and legal staff would review the contract.

"As long as it's an internal ownership change, I don't foresee the council getting a new vote on the contract but we will reread the contract to be sure," the mayor said.

City attorney Todd Greenburg declined comment on the issue.

Owners of the two teams that play at the Coliseum also don't believe any changes would affect their leases. The Bloomington Extreme indoor football team and the PrairieThunder hockey team both have two years left on those agreements.

"I have not been officially notified of any changes," said Ed Brady, principal owner of the Extreme. "But certainly we look forward to working with whoever is operating the Coliseum."

Tim Leighton, principal owner of the PrairieThunder, said he had not received notice of any changes at the building.

"I have heard chatter, rumors," Leighton said.

Butler and Nelson teamed up on the arena project in 2002. The 7,500-seat Coliseum opened in April 2006.

The pair, both Twin City natives, have spent much of their careers working in the sports entertainment field. Both worked for the two minor league teams in Peoria, the Rivermen and the Chiefs. Each also worked in local athletic programs - Butler at Bradley University and Nelson at Illinois State University.