Founder and CEO Mark Zuckerberg, who has mostly operated in the background during Facebook's closely watched journey to public markets, will be involved in the roadshow, another source said.

Facebook declined to comment.

Many on Wall Street had not expected Zuckerberg to turn up on the roadshow after he skipped a March analysts' meeting, ceding the stage to COO Sheryl Sandberg and CFO David Ebersman. His March absence irked some investors who were indignant that the CEO, while wielding near-absolute control over the eight-year-old firm, had snubbed Wall Street.

IPO roadshows, in which company management presents its strategy to prospective investors, typically last one to two weeks. If the roadshow goes particularly well, shares sometimes start trading a few days earlier.

Facebook is set to raise at least $5 billion in what will likely be the largest Silicon Valley IPO ever. The world's largest social network continues to command keen investor interest although disappointing first-quarter results raised questions about whether it can sustain breakneck growth for the longer term.

A source familiar with the offering said last week that a recent acquisition spurt by the company could have added about a week to the IPO timetable as regulators signed off on the deals.

This review is close to completion, however, allowing the company to go ahead with the roadshow on May 7, according to the source who spoke with Reuters on Tuesday. The sources did not want to be identified because they are not authorized to speak about the company's IPO.

"I have not seen as broad-based interest in an IPO since Google. Investor demand is immense," said Scott Sweet of research firm IPO Boutique. "I expect a roadshow that will rival all roadshows where investors will be turned away at the door."

The news on the road show was first reported by tech blog AllThingsDigital and the Wall Street Journal.

(Editing by Bernard Orr and Edmund Klamann)

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