Jeff Smisek will help mark his first day today as CEO of the world's largest airline, the new United Airlines, by flying aboard the first jet emblazoned with United's name and Continental Airlines' logo.

Today, Chicago-based United and Houston-based Continental legally marry in a deal first announced in early May.

With the simple act of signing paperwork at a Chicago law firm, a massive global carrier called United is born and Continental, which made Houston home since 1982, is now part of a Chicago-based operation.

Smisek, who led Continental, takes over the combination with much work to do.

"It's going to take time to bring the two companies together, time to bring the two cultures together and it will take time to bring the assets together and the technology together and all the things we do," he said in an interview with the Houston Chronicle. "Are there going to be issues? Sure. Will we be perfect? No. We're going to be very focused on getting it right."

Customers, however, shouldn't expect to see dramatic differences today versus Thursday as it will take months before the two airlines are fully meshed. For example, passengers will still buy tickets from United or Continental. In many ways, the two carriers will run as separate units of one company.

Bigger changes in spring

Continental passengers may know about the merger's closing and incorrectly assume they have to go to United's gate or check-in counter. So employees will direct customers to the right place, Smisek said.

"You're going to be very pleased as a traveler. Your travel experience is going to be a good one," Smisek pledged. "It will take us time to get there."

Significant changes are expected in the spring, on what the airline is dubbing "Customer Day One," when airport kiosks, airline websites and reservations systems will be combined.

"We're going to try to provide incremental benefits to customers as soon as we can," Smisek said.

For example, the new United will immediately adopt one of Continental's policies. United's Red Carpet Clubs in domestic airports will offer free alcoholic drinks, much as Continental's Presidents Clubs already do.

The merged carrier targets business travelers, who tend to be more profitable, he said.

Ultimately, the two carriers will merge frequent flier programs but Smisek stressed the new program will benefit customers. "Clearly, people's miles are safe and their status is safe. These are your best customers, your loyal elites and these are people you want to satisfy," Smisek said.

New logo debuts

Today, the first of United's fleet of 692 planes repainted with the United name and Continental's blue, white and gold globe logo will debut. Smisek will fly on that plane from Chicago to Houston this afternoon.

While at Houston and Chicago airports, he will meet with employees.

"It will be very important to make sure those employees are very well educated to handle customers' questions," said Vikas Mittal, a Rice University marketing professor. "Customers may have a lot of questions. (Officials) need to make sure all the answers they are getting are quite consistent."

The airline must also communicate changes to employees so they don't make mistakes, said Scott Sonenshein, a Rice University assistant professor of management, adding: "Change is distracting."

Employees will start noticing some changes today. Some workers will wear blue T-shirts with the new United logo. The airline will also have events for employees to meet their counterparts.

Airline officials haven't announced how many jobs will be cut but said Houston will continue as a major hub.

"We're going to continue to have an operation here in Houston," Smisek said. "The only jobs that will be affected in any number are the headquarters jobs in Chicago and here. The vast majority of jobs are untouched."

About 3,000 people work in Continental's downtown headquarters.

Some of the top officers not chosen to lead the new entity will leave today and some will continue at work for the next few months.

Continental's operations control center in Houston will move to Chicago's Willis Tower by 2012, when the carriers get a certificate from the Federal Aviation Administration to operate as one.

'We're well on our way'

Last year, United announced it would move its operations center from a Chicago suburb to the downtown Willis Tower, formerly known as the Sears Tower. Smisek will have an office in that tower as well as one in United's downtown Chicago headquarters. He will also keep his downtown Houston office.

By merging with United, Smisek hopes the larger airline will make money and sustain that profitability in an industry plagued by financial problems since the 9/11 terrorist attacks. He will earn a salary — something he gave up earlier this year - if the company turns a profit for the year.

"We're well on our way," Smisek said. "I hope to receive a salary this year."

On Thursday, the last day Continental's stock traded, it closed at $24.84, up 31 cents.

jenalia.moreno@chron.com