MGM Resorts International has been waiting and planning for the day the U.S. Supreme Court allowed sports betting, CEO Jim Murren told CNBC on Monday.

The nation's highest court ruled Monday that states can legalize sports betting, breaking up Nevada's monopoly on the practice.

"We have already established the architecture to deploy sports betting as soon as the states allow us to do that," he said on "Power Lunch."

"We have already the software. We have our mobile app called PlayMGM that is already activated in Nevada."

In its ruling, the Supreme Court upheld the legality of a 2014 New Jersey law permitting sports betting at casinos and racetracks in the state and voided the federal Professional and Amateur Sports Protection Act.

MGM certainly isn't the only company that prepared for the ruling. DraftKings CEO Jason Robins told "Power Lunch" on Monday that it also has been working on sports betting products.

"This is going to be a huge industry, and there will be a lot of competition which is great for consumers," Robins said.

Murren expects MGM to be "a very significant player, if not the largest player in this market" thanks to its "decades of relationships" with the sports leagues.

In addition to Nevada, MGM has casinos in Maryland, Michigan, Mississippi and New Jersey. It also has a "significant" online presence, he said.

Once states legalize sports betting, it would mean a notable increase in casino attendance as well as online visitors, Murren noted.

The end result would be "hundreds of millions of dollars in profit to the company."

In fact, when asked if he can imagine a day when there will be an MGM betting window at Madison Square Garden in New York, Murren replied, "yes, I can."

"It's all about fan engagement, getting people to watch these games point to point and to follow teams more passionately then they currently do. That will benefit the teams, the leagues and the consumer," he said.

"In many cases, MGM many not have a casino in that state but certainly we'll have a major presence. That's the big opportunity that we see," he added.

MGM's stock jumped Monday on the news, closing 1.6 percent higher.

— CNBC's Michael Sheetz contributed to this report.