WASHINGTON (Reuters) - Sen. Barack Obama announced on Sunday he had raised $32.5 million for his presidential campaign in the past three months, the biggest quarterly fund-raising for any Democrat ever in a pre-election year.

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The Illinois senator said more than 154,000 donors had contributed to his campaign for the Democratic presidential nomination in the April-June period, bringing his total donor list to more than 258,000.

Obama and Sen. Hillary Clinton of New York led all Democrats in the first quarter of the year with the former first lady edging out Obama, $26 million to $25 million. Only Republican President George W. Bush has raised more in the year before a presidential election.

Clinton, who leads Obama in national opinion polls, had not immediately released her figures but her campaign last week said she expected to raise $27 million to $28 million in the second quarter.

Candidates for president must report their fund-raising activity every three months. The second quarter ended at midnight on Saturday.

Donors can give up to $2,300 to finance a candidate’s primary race and another $2,300 for the general election if the candidate gets the party nomination.

Obama said of his $32.5 million he raised this period, $31 million was for the primary race against Clinton and six other Democrats.

“We now have hundreds of thousands of Americans who are ready to demand health care for all, energy independence and an end to this war in Iraq,” Obama said in a statement. “That’s the kind of movement that can change the special interest-driven politics in Washington and transform our country.”

With the November 2008 elections still 16 months away and the first primary votes more than six months from now, fund-raising has become a political barometer of how candidates are faring.

A strong performance can provide a spark for the campaign and bring in more support and donors. A less successful effort can raise questions about a candidate’s staying power and whether his or her campaign can last.

The other Democratic and Republican candidates will come forward with their totals over the next couple of weeks.

Former Sen. John Edwards, the Democratic vice presidential candidate in 2004, said he had reached his goal of $9 million in the second quarter. But that would fall short of the $14 million he reported the last time.