The Atlanta Falcons moved a step closer toward a possible new home field Tuesday, after the Georgia World Congress Center Authority signaled it is ready to move into detailed talks on the matter.

The Authority agreed to enter into a “memorandum of understanding” with the Falcons on plans for a potential $700 million open-air stadium downtown.

Both parties emphasized the memorandum does not constitute a done deal, but rather allows them to begin negotiations over details of the project, including financing.

But the Falcons have made it clear that they want a new open-air stadium, rejecting alternatives such as expanding the Georgia Dome, adding a retractable roof to the facility or building a new dome with a retractable roof.

A new stadium could open as soon as 2017, officials said, and would be built on a site just over a half-mile north of the Georgia Dome.

“We appreciate the Authority’s diligence in working through this process in a thorough and thoughtful manner,” the Falcons said in a statement. “We continue to have open dialogue with the Authority on a range of topics and options, with the shared goal of working toward an agreement that is in the best interests of the community, our fans and all other stakeholders involved. At this point, no decisions have been made; therefore, we will have no further public comment at this time.”

Tuesday’s action was the first time the GWCCA committed to actively plan for the Falcons’ future, not just study stadium alternatives.

The next step, officials said, will be for Falcons and GWCCA leaders firm up plans for the facility, iron out revenue sharing, work out how much the state and the Falcons will pay toward construction and determine lease terms.

Also in the mix could be naming rights for the facility, the field and the scoreboard.

The Authority, a state agency that operates the Dome, approved the agreement after Kansas City-based architecture firm Populous, which has been studying future plans for the Congress Center and its relationship with the Falcons, delivered its look at the viability of an open-air stadium.

The firm said a new stadium could fit on the Congress Center’s Marshaling Field -- an area where trucks are parked during conventions -- on Ivan Allen Boulevard between Marietta Street and Northside Drive. The stadium would have 65,000 permanent seats, 10,000 temporary seats, 7,500 club seats and 110 suites.

Walkways would be constructed over the streets for pedestrians, who would face a much longer trek from the nearest MARTA rail station than they have now to the Georgia Dome.

A.J. Robinson, president of Central Atlanta Progress, said he hopes a new stadium would be linked to efforts to revitalize surrounding areas.

“First and foremost, we need to do everything possible to keep the Falcons in downtown Atlanta and in the center of our region,” Robinson said. “It could have tremendous positive impact on our community. If you spend that kind of money, you really want to make sure you get it right.”

The plan would leave the Georgia Dome standing. GWCCA officials have argued that they would lose money if the facility, built in 1992, was torn down. Big tournaments such as the SEC football championship, the Chick-fil-A Bowl and the Men’s Final Four and ACC basketball championships have all played at the Dome because they prefer an enclosed stadium.

The state last year helped any potential agreement between the GWCCA and the Falcons clear its first hurdle when the General Assembly approved extending the bonds paying off the Dome. Those bonds, being paid off with hotel/motel tax collections, were to sunset in 2020, but will now end in 2050.

The Falcons, in return, have agreed to stay downtown on the GWCCA campus.

Authority member Bob Prather said if the parties agree on a new stadium, the state or the GWCCA would go to the bond market probably in 2013 or 2014 when officials hope they can raise $350 million to $400 million. Construction would begin shortly after the bonds are secured.

The Falcons would kick in the remainder of the funds, the Authority said.

Falcons owner Arthur Blank has hinted at his desire for a new stadium at least since 2008. Industry observers said the reason for this includes his desire for a better revenue-sharing agreement with the GWCCA, the ability to offer suites at a higher cost to shield the well-heeled from the elements and to snag a Super Bowl, which the NFL has been granting to new facilities.

It also would allow the Falcons to downsize the stadium, an industry trend. The idea is to offer fewer seats at a higher premium.

“My personal opinion, the Falcons are probably in a reasonable driver seat where they want to be,” said Bob Hope, president of public-relations firm Hope Beckham and a sports marketing guru.

Greg Beadles, chief financial officer for the Falcons, said an open-air stadium could open the door to a much talked about MLS soccer team in Atlanta, one of the city’s missing sports franchises.

“It’s good that it’s staying downtown,” Scott Condra, senior vice president of development for Jacoby Development, said of the Falcons stadium. “That’s very positive.”

Jacoby is vying with two other large firms to build a transit station near CNN Center on a site known as “the gulch.” The huge transit development would be just blocks from the new stadium.

“As we’ve gotten into this more, we’re more and more excited about the long-term potential” of the site, Condra said. “There’s a lot of potential in downtown.”

At $700 million, the new stadium being considered would cost far less than some recently constructed facility. Dallas Cowboys stadium in Arlington, Texas, cost $1.2 billion while New Meadowlands Stadium, home of the New York Giants and New York Jets, cost an estimated $1.6 billion.

Not everyone sees Tuesday’s GWCCA developments as positive.

“Be very careful about assuming there will be this massive economic impact in the community,” said Rick Burton, professor of sport management at Syracuse University. The key question is whether spending on a stadium crowds out investment in other big projects, such as manufacturing plants or hospitals.

Billion-dollar stadiums are now de rigueur, Burton said. “That’s the price of keeping up with the Joneses, literally.”

Burton questioned whether the Georgia Dome would be useful if it is not used for football. “In a lot of cases, these things become white elephants,” he said of football stadiums without football. “The cost per square foot to rent it is through the roof, because you’ve lost your major tenant.”

Andrew Zimbalist, a professor of economics at Smith College, said stadiums tend not to promote economic development. Depending on the financing, they can be fiscal drains, he said. But there are many variables such as cost overruns, sales tax exemptions and maintenance obligations.

Contributing: D. Orlando Ledbetter