“Nevada is clearly in our sights,” Murphy said Wednesday at the Betting on Sports America conference in Secaucus, N.J. “We can overtake it, according to experts, as early as next year.”

Since sports betting became legal in New Jersey in June, gamblers there have wagered about $2.3 billion, according to the New Jersey Division of Gaming Enforcement. In Nevada, gamblers bet about $5 billion last year.

Sisolak, in response to Murphy’s comments, said in a statement that Nevada would likely continue to benefit from the spread of legalized sports gambling. “We welcome New Jersey to the exciting sports betting industry,” Sisolak said. “Nevada understands that any success they experience will grow the gaming industry for all of us.”

Along with Nevada and New Jersey, six other states allow sports wagering and a handful of others — Montana and Iowa among them — are debating legalization laws. If New Jersey continues to grow its market share, it conceivably wouldn’t take long to reach the $5 billion mark.

But passing $5 billion doesn’t necessarily mean passing Nevada, where sports betting revenue has been steadily growing. According to the Nevada Gaming Control Board, the state took in $2.7 billion in sports wagers in 2010 and has grown the total each year since.

Just the same, William Hill US CEO Joe Asher said he also expects New Jersey to overtake Nevada. William Hill operates sportsbooks in both states.

The New Jersey market “is more than two times the size of the Nevada market,” Asher said. “You also look at the popularity of sports in the Northeast, the iconic teams there and the weather — that market is going to grow.”

Asher said, however, he doesn’t “view this as a rivalry because legalized betting is good for both states. If you look at Nevada, we just had our best March Madness ever. Nevada has provided the blueprint for other states to follow.”