WASHINGTON (CNN) -- The Federal Elections Commission slapped a conservative group that raised several million dollars in the 2004 election with a steep fine Wednesday in relation to alleged campaign finance violations.

The Progress for America Voter Fund -- which raised $45 million in the 2004 election cycle -- has agreed to pay the FEC $750,000 "to settle charges that it failed to register and filed disclosure reports as a Federal political committee and accepted contributions in violation of Federal limits and source prohibitions," according to a statement released from the FEC.

The FEC said the group should have registered as a federal political committee -- subject to contribution limits -- since "its major purpose is involvement in campaign activity." Instead the group registered as a '527' organization and was therefore tax exempt and free from contribution limits.

The fine is the third largest civil penalty ever leveled by the commission, according to the statement.

Despite agreeing to pay the fine, the Progress for America Voter Fund says it is not admitting to "any wrong doing," and blames poor FEC guidance for the infractions.

"Despite Congressional pressure to impose some set of rules or provide guidance for so called '527' groups, the FEC still refuses to do so," the group's legal counsel Benjamin Ginsburg said in a statement posted on the groups website. "Given the ambiguous legal nature of this situation and the cost of litigating this dispute, PFA-VF has decided it is a more prudent use of its resources and energy to conclude this proceeding."

FEC release

The Progress for America Voter Fund statement

-- CNN Ticker Producer Alexander Mooney