A bill to pump $360 million into a proposed Chinese air freight hub in St. Louis stalled on the legislative runway Friday. Now local business leaders are scratching for a way to keep the hub project from collapsing.

The clock expired on the so-called Aerotropolis tax credit package when the Missouri Legislature adjourned Friday evening, with House and Senate legislators stuck in an impasse over several economic development programs. Its supporters said the measure was essential to bringing Chinese cargo flights - and investment - to Lambert-St. Louis International Airport. Losing it will hurt.

But after three and a half years on the project, they weren't quite ready to give up, even if they're not yet sure of their next move.

"What happens next? I don't know," said Mike Jones, chairman of the Midwest China Hub Commission. "But I would hope we're not Humpty Dumpty and the pieces can't get put back together again."

Several Aerotropolis backers took heart in the fact that their bill had strong support in both the House and Senate - it simply got caught up in prickly negotiations about Missouri's Historic Tax Credit Program, negotiations that went on behind closed doors until the session's closing minutes.

"If the House and Senate were miles and miles apart, that would be one thing. But they were really close at the end," said Jeff Rainford, chief of staff to St. Louis Mayor Francis Slay. "We just ran out of time."

Rainford and Jones were hopeful for a special session, where legislators might iron out their final differences. Gov. Jay Nixon, however, was cool to the idea Friday evening, saying he needed to see "consensus" before he would call for a return to the Capitol.

In recent weeks, Aerotropolis supporters have painted the bill as a must-do, especially if Lambert hopes to grow the effort from a few flights a week into a true hub. Chinese airline officials said as much in a March letter to Slay, after they heard details of the plan.

The incentive plans "are truly wise and innovative," China Cargo executive vice president Gao Pei wrote, in a copy of the letter supplied to the Post-Dispatch. Without them, "opening a new air route to St. Louis will be very difficult, or even inconceivable."

It is unclear how much of that stance is negotiation and how much is reality.

Negotiators for Lambert could get a better sense of that later this month, when China cargo executives are scheduled to visit St. Louis for another round of talks. The airport had hoped it could present them with a brand new incentive package. Now those odds look slim.

For some time, local leaders have been confident that they can land a few flights a week, even without the tax credits. But that wouldn't provide the economic boost of a true hub, which, along with Aerotropolis-funded warehouse and manufacturing facilities, could by itself eventually generate more than 6,600 jobs, according to a recent study by the Regional Chamber and Growth Association.

The potential is there. Cargo experts say the Chinese want to dramatically increase the amount of U.S.-China air freight that flies on Chinese-owned planes, as opposed to U.S. or European carriers such as FedEx and DHL. Today, Chinese airlines control about 20 percent of the market. Their goal is a 50 percent share.

Routing much of that cargo through a single airport makes sense, experts say. Lambert - centrally located and underused - makes sense as a place to do it. It's a great opportunity for St. Louis, said RCGA president Richard Fleming, but one that could easily pass the region by if nothing happens soon.

"Pretty soon we're going to have to show an ability to do this deal or we're going to lose the customer," Fleming said. "It would really be a shame."