CHICAGO It took two years to erect what was once the tallest building in the world. It may take a bit longer for the public to take to its new name.
On Thursday, the 36-year-old Sears Tower becomes the Willis Tower, named after the world's third-largest insurance broker, Willis Group Holdings Ltd.
Public relations experts, academics and local historians said it could take decades for the new name of the 110-story skyscraper to take its place in the public consciousness.
"The Sears Tower is not just a Chicago landmark, it's a national landmark that's known around the world," said Aaron Perlut, a managing partner at St. Louis-based PR agency Elasticity. "We see it on our TVs, in movies and magazines, so it is part of pop culture."
"Gaining public acceptance of renaming the Sears Tower will be extremely challenging," he added. "Even with a very long, integrated marketing campaign we could be looking at a 20- to 30-year period."
Protesters of the name change started a Web site, www.itsthesearstower.com, boasting 34,000 signatures on an online petition.
Willis' chief executive said he understood the fuss after the original name-change announcement in March, but said the firm, which has leased some 140,000 square feet (13,000 square meters) in the skyscraper, is committed to Chicago.
Joe Plumeri, the CEO of London-headquartered Willis Group, acknowledged it could take time to win over Chicagoans.
"Nothing big is easy," he said.
The 1,450-foot sleek, black skyscraper was commissioned by Sears Holdings Corp, once America's largest retailer, at a cost of more than $175 million.
The foundation and floor slabs required 2 million cubic feet (56,600 cubic meters) of concrete, enough to build a 5-mile stretch of eight-lane highway.
Sears left the tower for a new suburban Chicago headquarters in 1991. In the meantime, Sears has lost ground to retailers like Wal-Mart Stores Inc and Home Depot Inc.
Even after Sears departed, the tower that tops Chicago's impressive skyline kept its name, attracting thousands daily to gape from its observation skydeck, the highest in the Western Hemisphere. This is the prize Willis seeks.
"When you have the chance to have your name attached to a building of that stature, it really says something about your company," Plumeri said.
Willis is paying about $24 million a year for the office space. Details on the price for the naming rights have not been disclosed.
Plumeri, for one, said he does not mind tongue-in-cheek references to Willis Tower as "Big Willie."
Willis' entry will be accompanied by a burst of philanthropy: $100,000 donations to Chicago's bid to host the 2016 Olympic Games and to a local volunteer organization.
Jamie Born, head of Born Public Relations, said even a strong marketing campaign may not win over all Chicagoans.
"Some people will never embrace the Willis Tower no matter what," she said. "But not much can be done about that."
Timothy Calkins, a marketing professor at Northwestern University's Kellogg School of Management, said the formal name change on Thursday may reignite public outcry.
"I fear an abrupt change will result in a negative backlash," he said. "People have strong feelings about this."
Locals on the street appeared to share that opinion.
"Why are we letting a British company do this to our biggest landmark?" said Shelley Anderson, 32, an office clerk. "It's the Sears Tower. It always will be."
Chicago has had its share of landmark name changes.
The Aon Center, the skyscraper that is home to insurance broker Aon Corp, was originally the Standard Oil Building and nicknamed "Big Stan." Few recall that moniker.
Many fans still call the home stadium of the Chicago White Sox baseball team Comiskey Park, and not the more corporate Cellular Field adopted in 2003 for sponsor United States Cellular Corp.
Renaming a landmark like the Sears Tower presents a challenge, Chicago History Museum curator John Russick said.
"To Chicagoans this is not just a commercial building. It is a monument to who we are and the kind of city we live in," he said.
"What's in it for the rest of us to call it by the new name?" he added. "It could be that in 40 years people will call it the Willis Tower, but it will take a generational shift for it to happen."
(Editing by Andrew Stern)