In a move that shows Republicans are coalescing around the party's front-runner, Mitt Romney plans to begin raising money jointly with the Republican National Committee this week as both the candidate and the GOP brace for an expensive general-election fight against President Barack Obama.

The arrangement will allow top donors to write checks as large as $75,000 per person, by giving to party organizations in addition to the campaign. That's far more than the $2,500 ceiling that applies to individual donations to a presidential candidate for the fall election.

The move reflects a general clamor within the party to begin amassing the funds needed to compete with Mr. Obama's fundraising operation, Romney and RNC advisers said. "Our donors are ready to mobilize for November," said Andrea Saul, a Romney spokesperson.