Former Massachusetts governor Mitt Romney raised $18-million over the past three months after shifting his 2012 White House campaign into high gear.

Washington - Republican presidential hopeful Mitt Romney raised more than $18-million over the last three months, a total that dwarfed his Republican rivals but lagged some predictions.

Romney's second-quarter fundraising reinforced the former Massachusetts governor's role as early Republican front-runner. But it also raised questions about voter enthusiasm for the party's current field of White House hopefuls.

The Romney campaign said on Wednesday the $18.25-million came from all 50 states and the District of Columbia and represented primary donations, not funds for a prospective general election battle against Democratic incumbent President Barack Obama.

Some advisers and analysts had speculated that Romney could raise $30-million or more in the second quarter. Republicans said the sputtering economic recovery may be dampening giving.

“Part of it is the economy. People have less money to give on things like this,” said Romney fundraiser Lee Cowen.

A pillar of Romney's support comes from those on Wall Street, Cowen noted, many of whom he said feel “betrayed” by some of Obama's policies.

More Republican establishment figures are giving to the former governor this election season, he said.

Romney, who mounted an unsuccessful presidential bid in 2008, raised more money - $23-million - in the first fundraising quarter of 2007, according to Federal Election Commission records. Four years ago, he was less well known.

Still, those figures included some of his own funds. He did not contribute to his campaign for the second quarter of 2011.

The Romney campaign also said it ended the second quarter with $12.6-million in cash on hand.

The sum was at least four times larger than second-quarter fundraising totals for Romney's closest money race rivals, some of whom have only just entered the contest.

Former Minnesota Governor Tim Pawlenty reported raising $4.2-million last week, while Texas congressman Ron Paul's campaign said he collected about $4.5-million.

Jon Huntsman, the former Utah governor and US ambassador to China, formally entered the race on June 21 and has taken in $4.1-million, according to aides. But just under half of that is his own money.

Both Romney and Huntsman have large personal fortunes.

Minnesota congresswoman Michele Bachmann, a Tea Party favourite and formidable fundraiser, has yet to report her second-quarter takings.

Meanwhile, the Obama campaign's second-quarter goal is to raise $60-million including money from a joint account with the Democratic National Committee. - Reuters