AUGUSTA — The state panel regulating Maine election laws on Wednesday ratified a previous decision to fine the National Organization for Marriage $50,250 for violating campaign finance rules during the 2009 same sex marriage referendum, a move that will likely be appealed in Maine Superior Court.

The expected court appeal prompted the panel to temporarily suspend an additional requirement that the organization disclose its donors. The five-member commission said the decision to hold off on the names requirement was precautionary, because a law court could rule that the donors should be confidential.

The disclosure of the organization’s donors is at the center of a controversy rising from an investigation by the Maine Commission on Governmental Ethics and Election Practices that found that the organization concealed its operations and donors during its successful bid to overturn Maine’s same-sex marriage law in 2009.

The commission voted May 28 to require the organization to register as a ballot question committee, pay the fine and disclose its donors from the 2009 campaign.

During that meeting, the organization’s executives vowed to appeal the ruling and protect the anonymity of its donors, who they said would be subject to threats and harassment if their identities were made public.

The organization poured more than $2 million into the $3 million referendum campaign to overturn the same sex marriage law that legislators passed and Gov. John Baldacci signed. The law never took effect.

Walt McKee, chairman of the commission, said Wednesday he didn’t accept the organization’s dire prediction or its argument that it operated legally during the referendum. However, he acknowledged that the organization’s legal appeal could overturn the commission’s ruling, in which case the commission’s identifying of donors could not be undone.

“Once the bell is rung, you can’t un-ring it,” he said.

The commission and its staff already know the identities of the organization’s major donors, whose monies were transferred to a local ballot question committee, Stand for Marriage Maine, in 2009. The names were obtained through court discovery documents and the organization’s confidential tax records. The commission agreed to a confidentiality agreement that keeps the records, and the donor names, secret. The May 28 decision to fine the organization and make it register as a ballot question committee will make the donor names public, but not the tax records.

The Portland Press Herald has requested the names of the donors under the state Freedom of Access Act. The ethics commission denied the request, saying the information is shielded as sensitive financial information. The information will become public if the national organization complies with the commission’s ruling or if the ruling is upheld on appeal.

Immediately after the commission ruling, the marriage organization filed two retaliatory complaints with the commission claiming that groups supporting same-sex marriage violated Maine election laws more than four years ago.

In the complaint against the Human Rights Campaign and the National Gay and Lesbian Task Force, two national gay rights advocacy groups, the marriage organization’s executive director, Brian Brown, argued that the groups had acted the same way his organization did in 2009. John Eastman, an attorney for the organization, also argued that it had been singled out by the commission, a claim that could play into the organization’s legal appeal of the fine and the requirement to disclose the names of its 2009 donors.

The commission will take up the organization’s counter complaints during its July 31 meeting.

The $50,250 fine against the organization is nearly twice the largest previous ethics penalty against a state political action committee.