PORTLAND – A political action committee backing a proposed resort casino in Oxford has outspent an anti-casino PAC by nearly 18-to-1, with all of its money coming from the Las Vegas company that wants to build the gambling facility, according to campaign finance reports.

The Vote Yes on 2 for Maine committee said the entire $552,029 it raised during the period ending Sept. 30 was contributed on Sept. 15 by Olympia Gaming Maine LLC. The money was spent within a 15-day period, most of it for television, radio and newspaper ads.

Casinos NO!, the PAC opposing the $150 million project, reported raising $77,700 during the reporting period. With reported expenditures of $31,358, Casinos NO! said its cash on hand rose to $47,380.

Nearly half of the contributions came from L.L. Bean Chairman Leon Gorman and his wife, Lisa, of Yarmouth, who gave $40,000. Another family member, John Gorman of Yarmouth, donated $25,000.

Casinos NO! reported expenditures for campaign consulting and polling but none for advertising.

“We’re going to try to get up on the air in a couple of weeks, if we can. We’re not sure just yet,” said Dennis Bailey, a spokesman for the group.

Pro-casino spokeswoman Pat LaMarche said her committee saw no need to solicit money from prospective donors in the state. “This is a business that’s asking to come to Maine,” she said of Olympia.

LaMarche offered no estimate of the amount that Vote Yes on 2 for Maine was prepared to spend on its campaign but said it was ready to respond to any “October surprise” from the opposition.

Bailey acknowledged that the slumping economy has helped the pro-casino campaign, which has emphasized its promise of bringing 800 jobs to an area of the state sorely in need of economic development.

Opponents maintain that a casino is a bad deal for Maine because profits from slot machines and gambling tables would wind up in Las Vegas.

The casino question goes before voters in a statewide referendum Nov. 4.