MGM Resorts International once derided the casino-owning Mashantucket and Mohegan tribes’ pursuit of a third Connecticut casino as a plan to house “slots in a box” somewhere between Hartford and the state’s northern border.

Now, the Las Vegas-based gaming giant claims the tribes, the town of Windsor Locks and the Connecticut Airport Authority have been plotting “to transform Bradley International Airport into a ‘mega casino,’ as large as any in Las Vegas.”

MGM, which is building a $950 million resort casino in Springfield, Mass., just north of the Connecticut border, leveled the charge in a news release Monday, saying emails and other documents it obtained after filing a state Freedom of Information complaint “clearly reveal a flawed process” in which the parties involved in a Bradley casino proposal met secretly and planned “to skirt local regulatory reviews.”

The release followed MGM’s announcement Friday that documents show the CAA and the tribes want to convert Bradley “from an airport into a casino … with an attached airport.”

Among the documents is a rendering of an over-sized Bradley casino.

A spokesman for the tribes — the Mashantucket Pequots, owners of Foxwoods Resort Casino, and the Mohegans, who own Mohegan Sun — said MGM’s dissemination of the documents “reeks of desperation.”

“The airport’s interest in hosting this facility is well documented,” Andrew Doba said. “And despite reports to the contrary, these renderings were done to highlight possibilities at the transportation center, a site that is no longer under consideration.”

He said the scope of the Hartford-area casino envisioned by the tribes has never changed.

Referred to as a small- to medium-size “satellite” facility, the so-called third casino would carry a price tag of up to $300 million, the tribes have said. It would offer slot machines, table games and a limited assortment of amenities, including restaurants.

The CAA provided MGM with the documents MGM released to the media. The CAA continues to withhold other information in accordance with the recommendation of a Freedom of Information Commission hearing officer who heard MGM’s complaint in April. 

In her “proposed final decision,” the hearing officer, Lisa Fein Siegel, finds that much of the CAA’s response to the tribes’ request for casino site proposals should have been disclosed. A portion of the documents MGM sought, however, contain “trade secrets” and can be withheld, she says in her recommendation.

The Freedom of Information Commission is scheduled to act on Fein Siegel’s proposed decision when it meets Aug. 24, according to a commission spokesman.

Responding to MGM’s statement, Kevin Dillon, the CAA’s executive director, said the casino operator “completely mischaracterizes the Connecticut Airport Authority’s proposal for casino development at Bradley International Airport.

“This desperate attempt at fear-mongering is just another chapter in MGM’s increasingly alarming track record of distorting the truth to protect its business interests and maximize its financial gain at the expense of the CAA.”

Dillon said the CAA elected to release documents related to locating a casino at the ground transportation center since that plan was withdrawn. He said MGM’s characterization of the plan as “overshadowing the airport itself” was “disingenuous.”

Documents related to Bradley sites that remain under consideration are “properly exempt from disclosure,” Dillon said, citing the proposed FOI decision.

MMCT Venture, the tribes' third-casino partnership, also is considering other sites in East Hartford, Hartford and Windsor Locks. It is expected to choose one before the state legislature reconvenes next year. Any Connecticut casino on nontribal land would require the prior legalization of commercial gaming, which is now prohibited in the state.

Foxwoods and Mohegan Sun operate as tribal casinos that are subject to federal regulation.

b.hallenbeck@theday.com