WASHINGTON (Reuters) - Fundraising by Democratic "Super PACs" is off to a slow start for the 2012 campaign season, compared with aggressive efforts by Republican groups that plan to spend hundreds of millions of dollars in fights for congressional seats and the White House.
Three major Democratic groups said on Friday they raised a total of about $5.7 million in the first three months of the year, bu oyed largely by donations from labor unions and hedge fund managers but far behind rival Republican groups.
Majority PAC, focused on preserving Democratic control of the U.S. Senate, received $1.6 million in contributions in the first quarter of 2012, according to financial filings with the Federal Election Commission.
House Majority PAC, which aims to help Democrats regain control of the House of Representatives that they lost in 2010, received $1.5 million. American Bridge, a group that does research on rival Republicans, raised $2.6 million together with its non-profit arm.
The Democratic groups are working in tandem against several behemoth Republican groups such as American Crossroads, run by Karl Rove, a former top aide to President George W. Bush.
American Crossroads alone plans to spend more than $250 million on congressional and presidential campaigns for the November 6 election. Such independent Super PACs - which unlike campaigns have no limits on individual donations - will allow very wealthy donors to have a big say in shaping this year's elections.
Republican Super PACs, inspired by the emergence of the conservative Tea Party movement, led to painful losses for Democrats in 2010, when Republicans took control of the House.
The American Crossroads Super PAC reported having $23.6 million o n hand a t the end of February, its FEC filings show.
American Crossroads also has a non-profit arm that is not legally required to disclose its fundraising to the FEC. According to tax forms cited on Friday by The Washington Post, the non-profit group had raised more than $76 million by the end of 2011 after launching in May 2010.
The three Democratic Super PACs had a total of $5.4 million in cash on hand at the end of March, their FEC filings showed.
"As the presidential primary and races up and down the ballot have unfolded, one thing is clear: Republicans and their outside groups are going to spend an unprecedented amount of money to advance their right wing ideology," the Democratic groups said in a joint statement on Friday. "We are confident we will provide a countervailing force to these extreme agendas."
UNIONS, HEDGE FUNDS STEP UP
The largest share of contributions to the three Democratic PACs in the first three months of this year - about $1.4 million - came from labor unions, a traditional source of support for the party.
The biggest union donation was $500,000 from the Committee on Letter Carriers, which represents Postal Service workers, to the House Majority PAC. The PAC also received $125,000 from the Laborers' International Union and $100,000 from the American Federation of Teachers.
American Bridge received $100,000 each from the Service Employees International Union (SEIU); the National Education Association (NEA), the biggest educators' union; and public sector union the American Federation of State, County and Municipal Employees (AFSCME).
AFSCME and SEIU gave another $10,000 and $20,000 to House Majority, respectively.
The biggest individual donor was James Simons, a billionaire hedge fund manager, who gave $1 million to Majority PAC.
Another hedge fund manager, S. Donald Sussman, who is married to Democratic Representative Chellie Pingree of Maine, became the biggest donor to House Majority with his $250,000 donation.
American Bridge's top contributor was Anne Earhart, who gave $400,000 to the Super PAC. Earhart is the granddaughter of J. Paul Getty, the oil baron and founder of Getty Oil.
LAGGING BEHIND REPUBLICANS
Many Democrats staunchly opposed the controversial 2010 Supreme Court decision that paved the way for Super PACs by re moving li mits on how much corporations, unions and other outside groups could spend on helping politicians.
Many Democrats' disdain for the court ruling - along with their dismay at the barrage of PAC-funded attack ads that fed into th e bitter campaign for the Republican presidential nomination - put Democrats behind fundraising for PACs.
Leaders of Democratic PACs say many potential donors have not y et r ealized the urgency being felt by groups that support Democratic candidates.
That complacency has also haunted another major Democratic PAC - Priorities USA Action, which backs President Barack Obama - as Obama himself did not support Super PACs until February.
Priorities had $2.8 million in the bank at the end of February, according to its latest filing. The group is due to report its March numbers on April 20.
Priorities shares a fund with Majority PAC and House Majority PAC, called Unity 2012, giving donors a single place to send checks. At the end of March, this month-old PAC had just one donation, $100,000 from Florida-based law firm Morgan & Morgan, which was split between Priorities and Majority PAC.
REPUBLICANS STEP UP
The Republican National Committee, another engine of Republican Party fundraising for congressional races, on Friday marked its best fundraising month of the campaign season.
The committee, which has been digging itself out of a multimillion-dollar debt, said it raised $13.7 million in March, with debts declining by $1 million from February to $9.9 million at the end of last month.
The committee started fundraising jointly this month with Mitt Romney, the party's likely presidential nominee. It had $32.7 million in cash on hand at the end of March.
Its counterpart across the party line, the Democratic National Committee, received $7.1 million in contributions in February, with $21.2 million left in cash on hand at the end of that month. The DNC had $5.8 million in debt.
The RNC and the DNC are also due to file their official March fundraising reports with the FEC on April 20.
(Editing by David Lindsey, Peter Cooney and Eric Beech)