Consultants for the city-county Sports & Exhibition Authority recommended in a draft report sent to the state Bureau of Historic Preservation that Mellon Arena be demolished and the 28-acre Uptown site be developed, SEA officials confirmed Wednesday.

The report, according to Chris Cieslak, a consultant working with Oxford Development and the SEA, “evaluates several alternatives,” but concludes that the Penguins’ plan to demolish the arena and construct a mixed-use development on the site would have the greatest economic benefit to the region. A full copy of the report, which was sent to the preservation bureau last month, was not available.

Representatives from two groups seeking alternatives to demolition walked out of last night’s closed-door meeting with SEA officials and other interested parties because they said the historic preservation process is not being followed.

“Their process is designed to divide and conquer,” said architect Rob Pfaffman. “The democratic process is being badly managed and badly executed.”

The SEA has hosted six other closed-door meetings that included developers and preservationists. A public meeting was held in the lower Hill District last month.

The $321 million Consol Energy Center is set to open across the street from the 49-year-old arena this summer. The main tenant, the Penguins, own the rights to develop the property.

Pittsburgh Mayor Luke Ravenstahl, Allegheny County Executive Dan Onorato and other public officials have said Mellon Arena should be demolished to create room for retail and housing developments. The Sports & Exhibition Authority — whose members are appointed by the mayor and county executive — has the final say on what will happen but has not made public any decision.

The preservation bureau has 30 days to review the draft report, while a consulting firm hired by the two groups seeking alternatives to demolition completes its own study.

“Everybody’s trying to beat the clock now,” said Todd Poole, managing principal of 4Ward Planning, representing Preservation Pittsburgh and ReUse the Igloo. “Obviously, I think from the standpoint of my clients, they would prefer that the process not be rushed.”

Poole hopes to have a “fully fleshed-out analysis that covers all the bases that we’ve discussed to this point” by early July. Poole said the SEA consultant’s plan falls short of a full analysis of what could be done with the arena. He said adding more retail space to an area with vacancies is a poor idea.

Gary J. English, a Penn Hills resident who filed for the Igloo’s historic preservation and has attended the SEA’s closed-door meetings, wants Allegheny County voters to decide the fate of the arena with a ballot initiative.

“I think the whole process is a farce,” English said. “They had one public meeting in the Hill District, but (the arena’s) owned by the residents of the entire county.”