Republican Senate candidate Shane Osborn already has raised nearly $234,000 for the 2014 race.
Osborn, who notified the Federal Election Commission of his candidacy in early June, filed his early fundraising numbers with the FEC last week, campaign manager Dave Boomer said Monday.
"We are off to a great start," said Osborn, who is a former state treasurer.
"We're making steady progress every day and will continue as we listen to and speak with Nebraskans who appreciate the importance of this election."
Omaha attorney Bart McLeay has announced his candidacy for the Republican nomination, and Ben Sasse of Fremont, president of Midland University, is undertaking a listening tour across the state before deciding whether to enter the race.