(Undated) -- LinkedIn is announcing strong user growth and better-than-expected third-quarter revenue. However, it issued a conservative revenue forecast for the fourth quarter and the 2013 fiscal year. The company on Tuesday reported revenue of 393-million dollars in the third quarter. That's a 56-percent increase from last year. Monthly users jumped to 259-million. Still, chief executive Jeff Weiner is signaling that LinkedIn could eventually reach a saturation point among white-collar workers, particularly in the U.S., and has sought new sources of revenue growth.