CHICAGO (AP) -- Chicago touted its financial strength in the 2016 Olympic bid Friday, with organizers saying they have at least a $1 billion safety net if the games exceed the estimated $4.8 billion price tag.

Chicago is competing against Tokyo, Madrid and Rio de Janeiro. The four cities submitted their bid files to the International Olympic Committee this week before making them public on Friday.

"Our aspirations for welcoming the world to Chicago and the United States are represented in nearly 600 pages in this three-volume document," Chicago 2016 leader Patrick Ryan said at a news conference.

Chicago's bid, supported by President Barack Obama, proposes centering the games along the city's scenic lakefront. The IOC will choose the 2016 host city on Oct. 2.

Chicago organizers said their safety net for the games includes a $450 million "rainy day fund," as much as $375 million in IOC cancellation insurance, another $500 million in insurance coverage - and a "last-resort" $500 million guarantee of taxpayer money from the city of Chicago.

Olympic games are notorious for busting their budgets. The 2012 Olympics in London will cost an estimated $16.5 billion, three times its original estimate.

Chicago's Olympic organizers, meanwhile, expect to make a $500 million operating profit on the games that would run from July 22 to Aug. 7. The paralympics would run from Aug. 17 to Aug. 28.

Still, the ongoing economic crisis has cast its shadow over the city's bid. Ryan has said the bid committee was forced to adjust its surplus estimate from $725 million to $500 million because of a possible lower sale price of the Olympic village to a real estate developer for mixed-use housing.

Organizers are looking to bring in $705 million in revenue from the sale of 7.6 million tickets.

They're also counting on $240 million in private donations that include non-Olympics related naming rights for permanent structures or other building projects.

The IOC evaluation commission will visit Chicago on April 4-7.

© 2009 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.