The annual report by the financial consulting company identified the Asia Pacific region as the world's fastest growing gambling region with new resorts in the Chinese enclave of Macau as well as Singapore and Thailand helping generate increases of 15.2 percent annually. Revenue from the Asia Pacific region will hit $37.2 billion in 2012 compared with $18.3 billion in 2007.

Total gambling revenue in the United States will remain well ahead of other regions, growing at 4 percent annually from $60.3 billion in 2007 to $73.3 billion in 2012, the report said.

But tough economic times will lead to declining revenues in 2008 and 2009 in Nevada and Atlantic City, according to the report.

Mary Lynn Palenik of PricewaterhouseCoopers said the mortgage crisis and high gasoline and travel prices will lead to the decline.

"It translates into fewer U.S. travelers," Palenik said.

Palenik said international travelers won't pick up all the slack of lagging domestic travel.

The report predicts a turnaround for Nevada starting in 2010, with revenues expected to reach $14.8 billion in 2012 from $12.8 billion in 2007, an increase of 2.9 percent per year.

Atlantic City was seen generating $4.74 billion in 2012, down from $4.94 billion in 2007.

New casinos as well as licenses for online gambling and sports betting in the region encompassing Europe, the Middle East and Africa are expected to drive revenues in the region up 4.9 percent a year from $30.3 billion in 2007 to $38.4 billion in 2012.

Gambling revenue in Canada is seen rising to $6.2 billion from $4.6 billion, while in Latin America, revenues are expected to climb to $514 million from $297 million.

Regional U.S. casinos outside of Nevada and Atlantic City, not including tribal casinos, were seen gaining 5.3 percent a year to $20.6 billion.