“Let’s fly together” is the new slogan for what is expected to be the largest airline in the world and its operation headquarters will be located right here in Chicago.

United and Continental airlines announced in the early hours of May 3 the merger of the two companies. The fusion of the airlines will have United’s name, but Continental’s globe logo.

“The merger came together very quickly,” said Christen David, spokeswoman for Continental. “The Continental president and CEO, Jeff Smisek, reached out to Glenn Tilton, chairman, president and CEO of UAL Corp., on April 9, and the merger was announced [less than a month later].”

Smisek will be CEO and a member of the board of directors, while Tilton will serve as non-executive chairman of the combined company’s board through Dec. 31, 2012.

“Together, we will have the financial strength necessary to make critical investments to continue to improve our products and services and to achieve the sustained profitability,” Smisek said in a statement introducing the merger.

According to the statement, the merger was approved unanimously by the board of directors of both airline companies. The merger plans are expected to come to a close near the end of 2010.

“The deal will close fourth quarter of this year and then we would start the integrating process,” said Michael Trevino, spokesman for United Airlines.

United Airlines’ current headquarters will remain at 77 W. Wacker Drive, while the company plans to move its operations, which employ about 3,000 people, to downtown Chicago from the suburb of Elk Grove, Ill. Their operations headquarters will be in the Willis Tower, 233 S. Wacker Drive, according to a spokesperson from the Willis Tower.

“They are moving into 380,000 square feet at Willis Tower,” the spokesperson said. “The first phase of that will begin this fall.”

The CEO will maintain offices in both Chicago and Houston, according to a statement released by the merging airlines. However, according to David, it is too early to determine how Chicago employment will be affected.

“Front-line workers—pilots, flight attendants, baggage workers, people actually at the airport—will be minimally affected,” David said. “Principle reductions will be coming from retirement, attrition and voluntary programs.”

According to the merger statement, employees will benefit from improved long-term careers by providing performance-based incentive compensation programs.

As far as services for passengers on either airline, community routes are expected to stay the same for frequent flyers. There will also be more of an opportunity for people in the frequent flyer program to earn and redeem miles.

“Customers will have increased flight options with more opportunities to connect in cities and the pricing will be competitive,” David said.

In Chicago, there are currently  a combined 627 flights through United and Continental.

Besides the domestic flights, the combined airlines plan to increase service to Asia, Europe, Latin America, Africa and the Middle East with 10 hubs in the United States.

United and Continental airlines presently employ 13,600 people in Illinois, and the combined carrier will be the largest private employer headquarters in Chicago. The combined carrier will also serve Peoria,  Moline and Springfield, Ill.

As far as the impact on airports, Trevino said it will be a city decision, but it is too early to tell.

“The Chicago Department of Aviation wishes both United and Continental Airlines well, and looks forward to a continued partnership at O’Hare International Airport.” said Karen Pride, director of media relations for the Chicago Department of Aviation.