By Oliver Clark.

Missouri senators have passed a $480 million package of incentives today (April 28) in a move that could convince China Eastern Airlines to make Lambert-St Louis International Airport (STL) its principal cargo base in the US Midwest.

The Aerotropolis Trade Incentive and Tax Credit Act, authorises the creation of gateway zones at STL where shippers can receive $0.25 of credit for every kilo shipped on an outbound flight and credits equal to $0.30 per kilo of perishable goods shipped from the gateway.

From January 2013 owners of freight forwarding facilites within the zone will also be entitled to an exemption from state income and corporate franchise taxes for up to seven years.

The incentives could play a major part in convincing China Southern to base regular international cargo flights at STL, although airport director Rhonda Hamm-Niebrugge has stated the Chinese carrier would only be the first, with cargo airlines based in Brazil, South Africa and elsewhere expected to follow suit.

The bill was made subject to final amendments, including a provision authorising the Missouri Science and Innovation Reinvestment Act, (MoSIRA), giving incentives to the science and high-tech companies based in the state.

The Midwest China Hub Commission, a public-private partnership formed in Missouri, is working with STL to make the airport a gateway for Chinese freight exporters to access the major agricultural and industrial markets of the 'Heartland of America,' - the 20 states of the Midwest.

With regular services to China in place, STL would become a net attractor of capital investment to St Louis and Missouri and an aerotropolis based on time sensitive manufacturing and cold chain products is then expected to rise on the 12,000 acres of vacant land around the airport.

The bill's passage comes days after policy analysts Audrey Spalding and Christine Harbin from Missouri-based think tank, the Show-Me Institute, slammed the bill in their testimony to the Missouri Senate Jobs, Economic Development and Local Government Committee, saying it will be an unacceptable burden on Missouri taxpayers and far more costly than envisioned.

""Supporters of this project argue that it won't cost taxpayers a dime, but this is far from the truth. Tax credits are real money, and they do not appear out of thin air - they come from the pockets of taxpayers," a copy of their testimony reads.

"With a higher tax burden, Missourians inevitably scale back their spending and this economic activity is lost," it continues.