Mohegan Sun will seek a recount of all ballots cast in Tuesday's referendum in Palmer, Mass., where voters narrowly rejected its $1 billion casino proposal.

In a statement released late in the day Wednesday, Mohegan Sun said it had begun gathering the necessary signatures on petitions seeking the recount.

"Once completed, we will be filing those petitions with the Palmer town clerk and asking that the recount be performed as soon as possible," the statement said.

Also Wednesday, a Palmer pro-casino group said it, too, was prepared to petition for a recount and would ask the Massachusetts Gaming Commission to investigate "outside influences" in the referendum.

Jennifer Baruffaldi, spokeswoman for Citizens for Jobs and Growth in Palmer, declined to identify the outside groups it suspects of influencing the vote.

Shortly after the results of Tuesday's balloting were announced, Mohegan Sun officials said they would ask for a recount of votes in at least one precinct. They said poll-watchers and voters had observed "very troubling" technical problems with a voting machine in Precinct 2.

In its statement Wednesday, Mohegan Sun indicated it wanted a townwide recount, meaning all four of the town's precincts.

"We have great respect for the process and strong level of voter engagement on both sides of this issue, and believe this action is appropriate to ensure an accurate count of all ballots," Mohegan Sun said.

Recount petitions must contain signatures of at least 10 voters registered in each of the precincts where votes are to be recounted, according to Susan Coache, Palmer's town clerk. Recount petitions can be filed up to 10 days after the referendum, she said.

The referendum vote was 2,657 to 2,564 — 50.9 to 49.1 percent — against the casino.

Project opponents reveled Wednesday in their 93-vote victory.

"I'm ecstatic," said Iris Cardin, co-president of Quabaog Valley Against Casinos. "We were over at the store (the group's headquarters) watching as the reports came in Tuesday night, and at first they (Mohegan Sun supporters) were ahead. I was scared to death we weren't going to win. But a half an hour later, it all changed. People started going crazy."

Cardin said she knew the casino opponents were gaining ground in the days and weeks before the vote because of the respect Mohegan Sun and its supporters showed them.

"They're all-powerful, with their money, their glitz, their glamor — their double-talk," she said of Mohegan Sun officials. "But they seemed to be increasingly concerned about us."

In an exceptionally heavy turnout in a non-presidential election, 66 percent of the town's 7,900 registered voters cast ballots.

"It was such a close vote that the turnout probably helped both sides," Cardin said.

Tuesday's defeat of the Mohegan Sun proposal and East Boston voters' rejection of a casino project proposed for the Suffolk Downs race track that straddles the East Boston-Revere line shook up the hunt for Massachusetts casino licenses.

The elimination of Mohegan Sun leaves MGM Resorts' Springfield proposal as the sole candidate for the western Massachusetts license. Suffolk Downs, meanwhile, was said to be considering altering its plan to keep it within the confines of Revere, where voters approved the project Tuesday.

Suffolk Downs has been in the running for the sole Greater Boston license along with Foxwoods Resort Casino, which has proposed a project in Milford, and Wynn Resorts, which would put a casino in Everett.

MGM, Foxwoods and Wynn have yet to be deemed "suitable" to file final applications with the gaming commission, a hurdle Mohegan Sun and Suffolk Downs had cleared. Foxwoods also must win approval in a referendum in Milford Nov. 19.

b.hallenbeck@theday.com