Sale of Facebook stock predicted to start May 18

SAN FRANCISCO -- The roadshow for Facebook Inc.'s initial public offering is scheduled to start Monday, meaning the company's shares should begin trading May 18, a source familiar with the process said Tuesday.

Mark Zuckerberg, founder and chief executive officer, who has mostly operated in the background during Facebook's journey to public markets, will be involved in the roadshow, another source said. IPO roadshows, in which company management presents strategy to prospective investors, typically last two weeks.