AUGUSTA – In what is destined to be the most expensive referendum contest in the state’s history, those for and against the proposed Indian casino are filling and emptying their campaign coffers at record paces, raising close to a combined $7 million.

With still four weeks to go before Election Day, the fund raising already eclipses the previous record of about $6 million spent on the 1997 clear-cutting referendum.

Think About It, the pro-casino political action committee financed almost exclusively by in-kind contributions from the casino’s Las Vegas developer, spent more than $3 million in the quarter ending Sept. 30, bringing the group’s total expenditures to $4.7 million, according to documents filed Friday with the state’s Commission on Governmental Ethics and Election Practices.

During that same three-month period, Casinos No!, the aptly named anti-casino group, raised $1.5 million, bringing its total to more than $2 million. Half of the amount raised this quarter came in $250,000 donations from three donors, Delaware-based credit card giant MBNA; L.L. Bean executive Leon Gorman; and millionaire financier Donald Sussman, whose business is based in Greenwich, Conn.

Sussman, while a new donor to the Casinos No! campaign, is no stranger to Maine politics. He has spent more than $1 million on various campaigns since 1996, including the record-setting 1997 referendum.

With both sides pouring money – a combined $2.4 million so far – into media production and television advertising, voters have been inundated with disparate messages about the effects of the proposed $650 million tribal casino, the most likely destination for which is the struggling industrial town of Sanford.

On Nov. 4, voters will decide whether to allow the Penobscot Nation and Passamaquoddy Tribe to open a casino if part of the revenue goes to the state. According to supporters’ estimates, the state could stand to gain $100 million each year from the deal, which would require the tribes to pay the state 25 percent of the slot machine revenue from the facility.

If passed, the measure would amend the 1980 Maine Indian Claims Settlement Act by allowing the tribes, like many other federally recognized tribes throughout the country, to open a full-fledged casino complete with slot machines, poker tables, roulette wheels and the like. The two tribes stand to split $50 million a year in profits, according to supporters’ estimates.

Recent polls show the race tightening to a dead heat after early polls showed the pro-casino movement leading by as much as 20 percentage points.

With voters split, each side is honing its very different message. Casino supporters promise thousands of new jobs with the facility, which they say will attract much-needed tourism dollars at a time when the state is still in the economic doldrums. Those promises are empty, say opponents, who warn of long-term costs associated with increased crime and traffic as well as other social maladies should the casino find a home in southern Maine.

Casinos No! spokesman Dennis Bailey said Friday that, despite being outspent more than 2-to-1, he was pleased with the fund-raising efforts so far that have allowed the anti-casino group to warn voters of the “deceptive casino scheme,” the oft-repeated catch phrase in its television advertising.

“I’ve never seen anyone spend so much of their own money trying to ‘help’ Mainers,” Bailey said of the millions of dollars funding pro-casino efforts from Las Vegas development company Marnell Corrao. “Give me a break. He’s trying to help himself to our wallets.”

Erin Lehane, spokeswoman for Think About It, said the opposition’s flap over the project’s out-of-state connection was puzzling.

“It’s a really strange day when the state of Maine should shun an investment that’s going to produce 10,000 jobs,” Lehane said, adding that much of the opposition’s money comes from “out-of- state millionaires and businesses,” including Sussman and MBNA.

“We should be looking for outside investment to improve things in the state of Maine and create jobs, not oppose them,” she said.

At the end of the reporting period, Casinos No! had about $843,000 in the bank. Think About It, running a pay-as-you-go campaign, reported no cash on hand.

Several smaller political action committees on either side of the casino question also filed campaign finance reports Friday. The full reports are available at the ethics commission’s Web site at www.mainecampaignfinance.com/public/home.asp.