SPRINGFIELD — Gov. Pat Quinn is expected to sign a major economic development package into law Thursday, potentially paving the way for the construction of a large fertilizer plant in central Illinois.

The measure, which also includes language to jumpstart construction of a third Chicago-area airport in Peotone, provides tax breaks for the $1.4 billion urea production facility in the Douglas County community of Tuscola.

Delaware-based Cronus Chemical LLC has said it is looking to build in either central Illinois or in Mitchell County, Iowa. Illinois is offering an estimated $14.5 million in tax breaks and other incentives.

A spokesman for the newly formed company said the signing of the law will start the clock ticking on a final decision.

"We expect to make a site selection within 30 days after that," spokesman Dave Lundy said in an email.

Iowa officials have not revealed if they are offering Cronus a similar package. But state economic development officials indicated this week that they think the Mitchell County site is still an option for the company.

"We've not heard that we aren't in the running," said Tina Hoffman, spokeswoman for the Iowa Economic Development Authority.

Cronus Chemicals is owned by a group of Swiss and Turkish investors and headed by Erzin Atac. Lundy said Atac has been in the fertilizer business for three decades. He graduated from Clemson University in 1982 with a bachelor's degree in industrial management and Drexel University with a master's degree in international trade in 1984.

The facility is expected to open in early 2016. As many as 2,000 construction workers could be needed to build the plant. Up to 200 full-time workers would then be in charge of producing an estimated 800,000 tons per year of ammonia, most of which will be converted to 1.4 million tons of granular urea.

In addition to the money for Cronus and the long-planned airport in Peotone, Quinn's action will authorize financing for a new basketball arena for DePaul University near Chicago's McCormick Place convention center.

It also provides an avenue for Rosemont to upgrade its convention center, located near O'Hare International Airport.

The legislation is Senate Bill 20.

(Mike Wiser of the Lee Des Moines Bureau contributed to this report.)