Obama campaign manager David Plouffe is set to give a private presentation on the general election to a group of top Hillary fundraisers, in a session that is being described as an effort to bring the Clinton campaign's big-money people aboard, according to a top Obama fundraiser involved in the event and another person who was invited.

Obama's finance team has asked the Illinois Senator's major donors to contact leading Hillary money people they have relationships with and invite them to attend, this fundraiser tells me. "It's an effort by the Obama campaign to reach out to Hillary's major supporters to ask them for their help and to be involved in the general election campaign," he says.

The session, which is set for this Thursday afternoon in a midtown Manhattan law office, is the first formal effort to woo Hillary's top financial supporters, and sheds some light on how the Obama team plans to go about the delicate task of winning them over.

Rather than just sending out a mass email to Hillary's donor community, the Obama camp has asked its own major money people to personally reach out to donors in the Clinton camp and invite them to the event, thus putting a more personal touch on the efforts to woo them.

"It's really people leveraging their relationships," the Obama fundraiser tells me. "The [Clinton donors] will be more comfortable if they're contacted by people they know, rather than someone nameless and faceless to them. A lot of people [on both sides] know each other."

The Obama team is expected to invite to the event top national Hillary fundraisers like Hassan Nemazee, Robert Zimmerman, Alan Patricof and Maureen White. It's uncertain yet how many Clinton people will attend.

Obama's fundraisers have privately estimated that the Clinton fundraisers can raise from $50 million to $75 million for his campaign, and more for the Democratic National Committee. The Obama campaign declined to comment on the meeting.