PORTLAND – The $650 million casino proposed by the Passamaquoddy and Penobscot tribes would be a safe bet for investors in a region that can support several more casinos, the nation’s leading casino lender said Friday.

Banc of America Securities estimates New England’s casino market to be worth $5 billion, much of which remains untapped.

The region’s only casinos – Foxwoods and Mohegan Sun in Connecticut – together bring in $2 billion to $2.5 billion in annual revenues – leaving room for additional players, said William S. Newby, a managing director.

Although the market can support additional casinos, Maine would benefit from being the first to establish a foothold, Newby said.

“There’s clearly a first-move advantage,” he told reporters at a news conference before going into a closed-door meeting with Penobscot Nation Chief Barry Dana and the tribe’s lawyer, Tom Tureen.

Banc of America Securities has not been retained to finance the proposed casino in Sanford but has been in talks with the tribes.

Newby, whose company has led financing for 78 successful casino deals since 1995, said he envisioned that the proposed Two Tribes casino resort would be funded primarily through bonds sold to institutional investors.

There also would be a leasing component as well as traditional bank loans that could involve local banks, Newby said.

Because the bonds would be public, the casino would have to open its books to the Securities and Exchange Commission, he said. The casino would file quarterly and annual statements that could be reviewed by the public, he said.

Newby said the deal is attractive to investors even though proponents say it would be the nation’s most heavily taxed casino.

He conceded that a few casinos are taxed at a higher rate, but he said those are smaller and don’t compare with the Maine proposal.

The current proposal calls for 25 percent of slot revenues going to the state. Imposing a higher rate, or reducing the 20-year term of the casino agreement, could discourage investors, Newby said.

Dennis Bailey, a spokesman for Casinos No!, agreed that the casino would be good for the bank, investors and Marnell Corrao Associates, the Las Vegas company hired to design and build the casino.

But he insisted it would not be good for the people of Maine because they are being shortchanged. He said the tax rate for Dover Downs, which has a casino and horse track in Delaware, is 35 percent.

“I don’t like casino gambling as a tool for economic development. But if we’re going to do it, let’s do it with our eyes open. Let’s negotiate something that works for the state and protects the state’s interests,” he said.

Two Tribes Enterprises, comprising the Penobscot Nation and Passamaquoddy Tribe, has an option to buy 360 acres where the proposed casino and resort would be built near Sanford Regional Airport.

So far, Two Tribes Enterprises has submitted preliminary drawings of the project, which includes a casino, hotel, convention center, retail shops, golf course and 2,000-seat performing arts center.

This week, Two Tribes transferred $270,000 into an escrow account to be used by Sanford to pay for negotiators and attorneys, and for studies of the potential impact on infrastructure and surrounding towns.