(Adds more candidates' figures, context)
By Steve Holland and Lisa Lambert
WASHINGTON, Oct 15 (Reuters) - Jeb Bush, who has struggled to connect with voters in his bid for the Republican presidential nomination, reported raising $13.4 million in the latest quarter on Thursday, an amount that pales in comparison to the heady, early days of his campaign.
The closely watched Bush total was only one story line emerging as candidates rushed to send in their financial reports to meet a Federal Elections Commission deadline.
New York billionaire Donald Trump, the leader in the race for the 2016 Republican nomination, said he raised $3.9 million for his largely self-financed campaign.
The donations for the quarter, which included the month of August when much political activity slows for summer vacations, put Bush behind only retired neurosurgeon Ben Carson in money raised among the 15 Republicans seeking their party's nomination for the November 2016 election.
Carson's campaign raised $20 million, almost entirely from small donations. Carson campaign manager Barry Bennett said Carson aims to reach 3 million individual donors by the end of the year, and wants to have raised $100 million by the end of the first quarter in 2016.
Bush's campaign said he has $10.3 million in cash on hand.
His fundraising for the entire third quarter is only moderately more than Bush raised in the 16 days after he launched his campaign in July, when he pulled in $11.4 million.
In addition, Bush released the names of hundreds of people who have bundled together donations totaling $17,600 or more for his campaign.
While the Bush camp called it a landmark showing of transparency, campaign watchdog groups complained that releasing names at the $17,600 level made it hard to divine who were the mega-donors responsible for raising $100,000 or more.
Some Republicans appeared to be barely getting by. No Republican was within shouting distance of Democratic front-runner Hillary Clinton, who had $33 million in cash on hand.
New Jersey Governor Chris Christie brought in $4.2 million, Ohio Governor John Kasich had $4.4 million and Louisiana Governor Bobby Jindal took in only $580,000. Former New York Governor George Pataki reported $153,000.
Trump's campaign said he has $254,772 in cash on hand. "Mr. Trump made a contribution of $100,779 during this quarter and has personally spent $1,909,576 since launching his campaign," his campaign said.
The dip in the pace of donations for Bush reflected his decline in polls of Republican voters who so far are favoring political "outsider" candidates such as Trump and Carson.
Bush campaign manager Danny Diaz said in a memo to Bush donors, some of whom have been rattled by Bush's decline in support, that the former Florida governor remains in a good position to challenge for the nomination.
"We knew from the start this was going to be a hard-fought and close race, but few could have anticipated just how volatile this field would be," Diaz said.
The $13.4 million raised by Bush in the third quarter compared with $14.2 million raised in the same period in 2011 by the eventual 2012 Republican nominee, Mitt Romney, the Bush campaign said.
Senator Marco Rubio, a Bush rival for establishment Republican support and also from Florida, raised $6 million in the same period while reporting having $11 million cash on hand. Rubio's $6 million was even outpaced by Wisconsin Governor Scott Walker's total of $7.4 million for the quarter.
Walker, sinking in the polls and having run out of money, pulled out of the race last month. (Reporting by Steve Holland and Lisa Lambert; Editing by Christian Plumb, Leslie Adler and Ken Wills)
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