Although that is possible, Los Angeles would need to win over "a whole bunch of them," he said. "And all the other places that have had them in the past are still competing."
Liberman, L.A.'s convention marketing chief, has said the city could draw more than six new conventions annually, but he cautioned that there is "absolutely no guarantee" even that goal will be reached.
Most experts and city officials interviewed by The Times agree that moving the West Hall of the Convention Center and connecting its exhibition space directly to the large South Hall would improve the marketability of the facility.
Together, the halls have 770,000 square feet of exhibition space, making Los Angeles about 15th in the nation. The proposed retractable-roof stadium would increase the useable convention space to about 1.2 million square feet. But AEG acknowledges that in terms of flat, open exhibition space — the kind many exhibitors prefer — it would add only about 165,000 square feet on the stadium floor. That means Los Angeles still would not be among the top 10 cities in the nation, based on industry rankings.
"In the great scheme of space, it's not very much," said Heywood Sanders, a professor at the University of Texas at San Antonio and author of several critical convention center studies. "And it doesn't work out particularly well. It's not … particularly functional space to be on the [stadium floor] with a vast roof and lots of empty seats."
Two convention centers that use football stadiums for extra space — Indianapolis and Atlanta — illustrate the challenges AEG and Los Angeles could face.
Indianapolis' Lucas Oil Stadium added 183,000 square feet of exhibition space to its convention center's 566,000 square feet of floor space. But the stadium is off limits during about 47 training and game days during the Indianapolis Colts' season, according to Chris Gahl, a spokesman for the Indianapolis Convention & Visitors Assn. AEG says it expects to limit such disruptions with a separate practice facility.
The Atlanta Falcons' Georgia Dome added 102,000 square feet of exhibition space to its sprawling convention display areas, already the nation's fourth largest. But it is rarely used for such gatherings, because convention planners prefer the contiguous space next door at the Georgia World Congress Center, said Jason Kirksey, a Georgia Dome spokesman.
Los Angeles officials say the stadium would open the door for the largest gatherings, including major religious groups, which bring tens of thousands of attendees together for opening and closing ceremonies. And without the stadium project, they say, the city would have no money to fund costly Convention Center improvements needed to retain even existing conventions.
Leiweke and key downtown business leaders say a redone convention campus would drive development of new hotels, a long-time city goal thwarted by market conditions and difficulties getting financing.
But hotels survive on a balance of conventions, business travelers and tourists, which poses challenges in downtown Los Angeles, said Carl Winston, director of the hospitality and tourism management school at San Diego State. "Most tourists, when they think of L.A., don't think of staying downtown. They want to be by the beach, they want to be in West L.A., they want to be in Anaheim. It's not, 'Honey, let's take the kids and go visit the Dorothy Chandler Pavilion.'"
A stadium would make downtown a more vibrant hotel market, said James Butler, chairman of the global hospitality group at Jeffer, Mangel, Butler & Marmaro, a Century City law firm. "But I'm not sure that the market either needs four or five more hotels or that there would be enough business to sustain it."
The most difficult challenge, Leiweke says, will be getting another 1,000-room hotel to help anchor the largest conventions. That would probably require the city to add a financial incentive by reducing its customary bed-tax share, he said.
AEG's recently completed downtown hotels received such a subsidy. But with city services being slashed and with the city's budget shortfall estimated at $404 million, a push for more subsidies could prove controversial. Peter Zen, owner of the Westin Bonaventure, said he would probably fight efforts to give new hotels a tax break.
AEG said it supports a transparent review, but for now its officials declined to answer a number of questions, including whether the stadium would be profitable if increased convention business and construction of new hotels do not materialize as hoped.
The company also declined to describe the financial backup for its guarantee that no taxpayer money would ever be used for the project. It is not clear, for example, whether the assets of AEG or some form of letter of credit, bond or insurance policy would stand behind the pledge.
In a statement, AEG said it is confident that by the end of the approval process, the city and the public "will discover that there are no hidden secrets or agendas" and that the company stands behind its commitment to develop the stadium "at no cost and no risk to the tax payers."