BOSTON — Backers of two high-profile casino proposals were weighing their next moves on Wednesday after the projects were defeated by voters in local referendums, further shrinking the field of viable candidates to open the state’s first destination resort casinos.

Mohegan Sun said it had begun gathering signatures on petitions seeking a recount of votes in Palmer, where the Connecticut casino operator’s proposed $1 billion complex was rejected by less than 100 votes out of about 5,200 cast in the small western Massachusetts town.

Suffolk Downs, the 78-year-old thoroughbred race track which had staked its future on a $1 billion casino development, was mulling relocating the project to a 52-acre site in Revere, after East Boston voters rejected the current plan by a 56-44 percent margin despite the strong support it had from outgoing Mayor Thomas Menino and other political leaders.

If the proposals cannot be salvaged, the results of Tuesday’s votes mean there could potentially be few — if any — applicants for resort casino licenses in the eastern or western regions by the Dec. 31 deadline set by the Massachusetts Gaming Commission.

Stephen Crosby, the commission chair, said he was not worried by such a prospect.

“The chips, so to speak, are going to fall where they fall,” he said.

The Legislature and Gov. Deval Patrick legalized casino gambling in 2011, allowing for up to three regional resort casinos and one slots parlor. Prospective casino developers are required to win approval from voters in host communities and clear background checks before they can apply for a license.

“We’ve said many times, we are not pro-casino, we are pro-implementation of this law,” Crosby said of the five-member panel charged with overseeing the law.

Mohegan Sun was one of two developers seeking the western Massachusetts license. The other, MGM Resorts International, won approval from Springfield voters in July, but is awaiting results of the background check.

Suffolk Downs was one of three entities seeking the eastern license, along with Connecticut casino operator Foxwoods in Milford and Las Vegas casino operator Steve Wynn in Everett.

Both Foxwoods and Wynn are awaiting background check results. Wynn secured the support of Everett voters in June, and the Foxwoods proposal will be put to a vote in Milford on Nov. 19.

“There is a possibility that there could be no one left standing by Dec. 31,” noted Clyde Barrow, a casino gambling expert at the University of Massachusetts-Dartmouth.

Casino prospects in the third region, southeastern Massachusetts, remain in temporary limbo as the Mashpee Wampanoag tribe pursues state and federal approvals for a tribal casino in Taunton.

Crosby said Wednesday that the commission would be willing to consider a plan by Suffolk Downs to move its project entirely into Revere, where voters strongly approved a separate casino referendum on Tuesday.

Mohegan Sun was requesting the recount due to “possible irregularities” in Tuesday’s balloting, the company said in a statement.