Artist’s rendering of MGM National Harbor. (Courtesy of MGM Resorts International.)

[This post has been updated.]

The two gambling operators whose Prince George’s County casino-license applications were rejected by Maryland’s site-selection commission have agreed not to sue over the decision, according to state officials.

Penn National Gaming and Greenwood Racing each signed a “release and covenant not to sue,” clearing the way for MGM Resorts International’s proposed $925 million gambling resort at National Harbor.

MGM was awarded Maryland’s sixth and final casino license in December, beating out Greenwood’s pitch to build the $800 million Parx Casino Hotel and Spa in Fort Washington and Penn National’s proposed $700 million Hollywood Casino Resort at the historic Rosecroft Raceway.

“I am pleased that the applicants that were not selected felt that the award process was fair and balanced and there was no reason to challenge the commission’s decision,” Donald C. Fry, chairman of the state’s Video Lottery Facility Location Commission, said in a statement.

The state has returned a half-million-dollar “litigation/protest” bond to each of the two Pennsylvania-based companies — along with their initial licensing fees: $18 million to Penn National Gaming and $28.5 million to Greenwood Racing.

Stephen Martino, the state’s top gambling regulator, said in an interview that the Video Lottery Facility Location Commission’s “complete transparency throughout the licensing process” likely helped avoid legal entanglements. The site-selection commission held every one of its meetings in public, with no executive sessions, and posted voluminous consultants’ reports online.

“You can’t attack the process,” said Martino, director of the Maryland Lottery and Gaming Control Agency, which operates separately from the site-selection panel.

Representatives for Penn National and Greenwood were not immediately available for comment.

Penn National officials have been silent since the Dec. 20 decision. But Tony Ricci, chief executive of Greenwood, said in December that he thought the licensing process was fair.

“I’m sure MGM will give them a great product,” Ricci said.

MGM will break ground as soon as it receives clearance from the county but won’t open until mid-2016, at the earliest.

“Chairman Fry deserves credit for guiding the Commission, the bidders, and the public through a process that proved to be comprehensive, transparent, and inclusive,” said Lorenzo Creighton, president and chief operating officer of MGM National Harbor. “We are pleased at this news and can now focus on the significant task ahead of us – turning the vision of MGM National Harbor into reality.”

The lucrative Prince George’s County license created the first truly competitive bidding process for the site-selection commission: Maryland’s first five casino licenses were awarded to the lone final applicant.

But there were still lawsuits over some of the commission’s actions. The Laurel Racing Association sued to get back into the bidding for the Anne Arundel County license after its bid was thrown out for not including a required multi-million licensing fee. The Maryland Court of Appeals sent Laurel’s lawsuit back to the Anne Arundel Circuit Court and ordered it dismissed. The license was ultimately awarded to Cordish Cos., which built the state’s largest casino, Maryland Live, at Arundel Mills Mall.

A bid for a casino license in downtown Baltimore was thrown out in 2009 by the site-selection commission over financing delays and other issues; the developer, Baltimore City Entertainment Group, challenged the decision, but the

Maryland State Board of Contract Appeals ruled in the commission’s favor. Baltimore City Entertainment Group and another group later objected to the commission’s

eventual decision to award the license to a group led by Caesars Entertainment. But the Board of Contract Appeals dismissed those challenges, too.

The Horseshoe-branded Baltimore casino is expected to open in August.