ATLANTA - A sleek new $1.4 billion international terminal featuring airy windows and eye-popping artwork opened Wednesday at the world's busiest airport in hopes of positioning Atlanta to attract more globe-trotting travelers.

The sparkling launching pad has been in the works for more than a decade at Hartsfield-Jackson Atlanta International Airport. Besides helping to grab its share of the lucrative and growing international market, officials also hope the vast new terminal convinces Atlanta-based Delta Air Lines Inc. and other carriers to route more flights through the city.

"It's really going to open up new opportunities for Atlanta to grow," said airport general manager Louis Miller. "It's going to become a gateway not just to Atlanta, but to the world."

It's been a somewhat bumpy ride for the project.

It took four years to build, in part because it's so expansive that workers had to carve out a new entrance on a busy highway. It also came at a time when Delta is cutting back slightly on international flights to control rising fuel costs. Legal challenges threatened to derail it, and millions had to be spent on new signs simply to make sure travelers could find the place.

Mayor Kasim Reed said the massive investment of $1 billion in municipal bonds to be repaid by passenger fees and another $400 million picked up by the airlines will reap dividends long-term.

"This magnificent facility is an economic catalyst for the city of Atlanta, the state of Georgia and the entire southeastern United States, and it will help create jobs and new business opportunities for years to come," he said in a statement.

The project is actually two behemoth buildings.

The first is a light-filled terminal with broad glass windows along every wall and separate levels for arriving and departing travelers to help untangle traffic. The second is a new concourse with 12 gates, giving the airport a total of 40 international gates. That will allow airlines to offer new routes and relieve the strain on the airport's other five concourses that handle 2,500 flights a day.

At Wednesday's ceremony, hundreds of passengers and airline workers wandered through the buildings, visiting upscale retail outlets, eating at new diners and scoping out the artwork.

"It's great. It will be more convenient for us," said Raymond Lu, a 32-year-old chemical salesman from China who was waiting for the terminal's first departure bound for Tokyo. "It's easy, it's very convenient. But it's very strange being on this flight."

Some of the more popular features are behind-the-scenes upgrades. One is a new system that ends the baggage re-check process for Atlanta-bound international travelers, who previously had to relinquish their suitcases after clearing customs and then wait for them again at baggage claim. It will cut travel time by 45 minutes to an hour for international flyers whose destination is Atlanta.

The expansion helps Atlanta keep pace with other major international stops. Beijing's airport, the second-busiest on the planet, built a third runway and a colossal glass-and-steel terminal in time for the 2008 Olympics. And Chicago's O'Hare International Airport, the world's third-busiest, is undergoing a $15 billion expansion that will add a new runway and other upgrades.

The terminal's long-planned opening was touch-and-go for a bit. As workers scrambled to put on the finishing touches, a legal fight by concessionaires who lost bids to open stores and restaurants in the terminal threatened to delay the opening. They claimed that the city's contracting decisions were linked to political donations and connections, but their challenges have so far been denied or settled.

Other critics have raised concerns that the project is an unnecessary expense driven by a "pay-to-play" culture.

"It is not sound policy and good decision-making processes that lead to projects such as the new terminal, it's campaign contributions that fuel this decision and others like it," said William Perry, who heads the ethics watchdog group Common Cause Georgia.

City officials dismiss the claims, saying that Atlanta abides by a strict ethics law that's been in force for more than eight years. Atlanta spokeswoman Sonji Jacobs said the benefits of the terminal, named after ex-Mayor Maynard Jackson, will far outweigh its costs.