John Brunner opened his own wallet again to help finance his bid for the Republican Senate nomination in Missouri.

The St. Louis businessman gave $1.2 million from his own fortune, raising his personal contribution total so far to $2.2 million, based on the latest quarterly campaign expense reports filed with the Federal Election Commission. Brunner donated more than $1 million of his own money last year.

His latest donation dwarfed the amount he raised from contributors during this period, which came to $168,000. Overall, Brunner's campaign took in nearly $1.4 million during the first three months of the year.

A rival for the nomination, Republican Rep. Todd Akin, raised $416,580, according to his report. That's $1 million less than Brunner. The third GOP hopeful in the race, former state Treasurer Sarah Steelman, had a another disappointing quarter. She raised just $179,000.

Steelman only drew $84,000 in the final months of 2011. She reported $600,000 in her campaign bank account.

Akin, a suburban St. Louis lawmaker, has collected nearly $2 million so far and reported $1.4 million in cash on hand. Brunner, the former chief executive of Vi-Jon Inc., a St. Louis personal care products company, has raised more than $2.6 million so far and has $2.25 million in the bank, according to his report.

The winner of the battle will face Democratic Sen. Claire McCaskill. Her latest campaign numbers became public last week and she appears to be well ahead in personal fundraising. McCaskill has raised $2.3 million since January and has more than $6 million in the bank, according to the FEC.