PORTLAND – Casino supporters are quick to say a proposed casino in Maine won’t be like those in Las Vegas.

They’re right, at least in regard to its size.

A Maine casino as now proposed would have more floor space devoted to gambling than any casino in Las Vegas. It also would be among the top grossing casinos anywhere in the country.

According to a study commissioned by casino supporters, a casino with 4,000 slot machines and 180 gaming tables would generate close to $500 million in revenues its first year and more than $600 million by its fifth year.

That kind of money – while dwarfed by the Foxwoods and Mohegan Sun casinos in Connecticut – would rival the gambling revenues of the largest casinos in Atlantic City and exceed those in Las Vegas, casino experts say.

Casino supporters say the higher the revenues, the higher the taxes that go to the state and the more jobs that are created.

“What the numbers say is this is a huge opportunity for the state,” said Erin Lehane, spokeswoman for the pro-casino group Think About It.

Dennis Bailey, spokesman for Casinos No!, said the numbers have been inflated to seduce voters with promises of large payouts to the state and lots of jobs.

“These are trumped-up figures and it doesn’t take a marketing genius to figure out they’re way off the mark,” Bailey said. “They’re promising things they can’t possibly deliver.”

Mainers will vote Tuesday on whether to allow the Passamaquoddy and Penobscot Indian tribes to build a casino. The tribes want to build a $650 million casino and resort in southern Maine, with Sanford the likely location.

Foxwoods is the nation’s largest casino, with annual gambling revenues of more than $1 billion. Mohegan Sun took in nearly $960 million for its 2001-2002 fiscal year.

Outside of Connecticut, the largest casinos are in Atlantic City, where the top operations last year were Trump Taj Mahal (gaming revenues of $536.2 million), Caesars ($527.4 million) and Bally’s (526.7 million), according to the New Jersey Casino Control Commission.

Gaming revenues at a Maine casino would approach $550 million in its second year, according to an economic impact study by KlasRobinson QED, which was commissioned by casino supporters. By the fifth year, it would have estimated revenues of $610 million, the study says.

Jim Klas, a partner of KlasRobinson, a consulting company in Minneapolis, said doubters of the Maine estimates need look only as far south as Foxwoods and Mohegan Sun to see how high the numbers can go.

“Nobody 10 years ago would have projected a billion-dollar casino in this country – anywhere,” he said.

Jake Fuller, who tracks hospitality and leisure industries for Thomas Weisel Partners in New York, said it’s easy to project numbers for a casino.

“But attaining those numbers,” he said, “is a totally different thing.”

A 200,000-square-foot casino, as envisioned by the two tribes, is also large by Las Vegas standards.

The largest Vegas casino, MGM Grand Hotel/Casino, has 171,300 square feet devoted to gaming, according to the Nevada Gaming Control Board. Bellagio, Caesars Palace and Bally’s are among the other large Vegas casinos.

Bailey said the comparison to Vegas casinos shows that the size of the Maine casino proposal is out of proportion with the scale of things in the state. The proposed 875-room hotel, for instance, is more than three times larger than the state’s largest hotel, the 245-room Anchorage by the Sea in Ogunquit.

“I don’t think people have imagined how big this will be,” he said. “It seems to be out of proportion to the state.”

Top casino markets

Casino backers say a casino in Maine would generate revenues of close to $500 million its first year, which would make the state the nation’s 17th-largest casino market. The top casino markets are:

Las Vegas $4.7 billion

Atlantic City, N.J. $4.3 billion

Chicago area (including N. Indiana) $2.2 billion

Connecticut $2.0 billion

Detroit/Windsor, Ontario $1.4 billion

Tunica/Coahoma, Miss. $1.2 billion

Mississippi Gulf Coast $1.15 billion

Reno/Sparks, Nev. $961 million

Shreveport, La. $806 million

Southern Indiana $788 million

Source: American Gaming Association

Most slot machines

Casino backers in Maine want to build a casino that would have 4,000 slot machines. The casinos nationwide with the most slot machines are:

Foxwoods, Ledyard, Conn. 6,600

Mohegan Sun, Uncasville, Conn. 6,200

Silver Star/Golden Moon, Philadelphia, Miss. 4,850

Trump Taj Mahal, Atlantic City, N.J. 4,826

Soaring Eagle Casino, Mt. Pleasant, Mich. 4,704

Tropicana Casino and Resort, Atlantic City, N.J. 4,495

Harrah’s Atlantic City, Atlantic City, N.J. 4,200

Borgata Hotel Casino, Atlantic City, N.J. 3,650

Harrah’s Cherokee Casino, Cherokee, N.C. 3,600

Source: KlasRobinson Q.E.D.