CHICAGO. August 5, 2009. UAL Corp. plans to lease about 450,000 square feet in Willis Tower (formerly Sears Tower) in a deal that will bring 2,800 jobs downtown and is to include about $25 million in city subsidies through a tax-increment financing (TIF) grant, sources say.

UAL will move its massive operations center out of its former headquarters in Elk Grove.

It was reported Wednesday that UAL executives said the decision was driven by economics, because the airline would have to spend $50 million to upgrade the Elk Grove Township operations center.

Alderman Robert Fioretti (2nd) confirmed UAL was seeking $25 million in TIF funding and said the mayor’s office was planning a formal announcement for Thursday.