Republican Mitt Romney, who has a net worth estimated at up to $350 million, said Monday he has given money to his presidential campaign for a second time and may do so again before this weekend's fundraising deadline.
The former venture capitalist declined to say how much money he has contributed, although the financial reports he has to release within weeks will reveal the amount.
The second-quarter fundraising period for all candidates ends Saturday.
Romney said an unprecedented $4 million that he spent on early advertising forced him to make the personal contributions. The former Massachusetts governor served only one term in elected office and started the campaign largely unknown outside his home state.
"One of the things I've had to do that you don't have to do if you're name is McCain or Giuliani is introduce myself to people in Iowa and South Carolina and New Hampshire," Romney said, referring to his rivals John McCain and Rudy Giuliani.
Romney revealed the donation as his supporters sought contributions from their friends and business colleagues at an event in TD Banknorth Garden, home to the Boston Celtics and Boston Bruins.
Romney sought to lower expectations, telling reporters, "I don't know how much we're going to raise here. If we do a million, that would be terrific. If we do more than that, that would be fabulous."
He also predicted his second-quarter report would show he had raised substantially less during the quarter than his total for the first three months of the year.
His staff said they expect donations to lag because Romney spent more time making speeches and preparing for the primary campaign's first two nationally televised debates. Interest among conservative donors in former Tennessee Sen. Fred Thompson, who is expected to announce his own campaign next month, was also a factor.
During his first "National Call Day" in January, Romney raised $6.5 million, helping to propel him toward a record $21 million in fundraising. He also contributed $2.35 million to his campaign, giving him a first-quarter total of $23 million.
At the time, Romney said "it would be akin to a nightmare" if he had to donate to his committee - even though he had already done so when he made that comment to reporters. He later said the donation was needed to seed his campaign with computers and other infrastructure.
On Monday, Romney said he had donated again, and may do so yet again before Saturday's deadline. He would not say if he had made loans or outright donations. He is not limited in how much he can give to his own campaign.