MGM Mirage (MGM) said the lawsuit from its joint venture partner alleging the troubled casino operator breached the terms of their $8.6 billion CityCenter development in Las Vegas is baseless.

Dubai World said Monday its Infinity World Development Corp. unit is suing MGM for an undisclosed amount and asked the Delaware Chancery Court to free it from making future payments and fulfilling other obligations under its partnership deal with MGM Mirage.

"The lawsuit filed yesterday by a subsidiary of Dubai World is completely without merit. Dubai World is well aware of our written commitment to meet our funding obligations and that MGM MIRAGE has available cash to satisfy those obligations," said Alan Feldman, a MGM spokesman, in an emailed statement overnight.

"MGM MIRAGE is ready, willing and able to fund its share of the costs to complete CityCenter, including a required payment this week," the statement said.

In the lawsuit, Dubai World blamed MGM for massive cost overruns on CityCenter. Dubai World owns a 50% stake in the project and controls about 9.4% of MGM Mirage shares.

The lawsuit came nearly a week after MGM's auditor raised doubts about its ability to continue as a going concern amid a brutal gaming environment and remarks by MGM Chief Executive Jim Murren which described the company's relationship with Dubai World as "outstanding."

-By A.D. Pruitt, Dow Jones Newswires, 201-938-2269, angela.pruitt@dowjones.com