According to analysts surveyed by Bloomberg, third-quarter revenues are expected to have risen 29 percent to 1.23 billion dollars, when the company delivers results on Tuesday.
That is down from a 32 percent rate that Facebook achieved in the second quarter, the Telegraph reports.
According to the paper, the US-based social network will also report a quarterly profit of 284 million dollars compared with a loss of 157 million dollars in the second quarter.
The anxiety over the pace of revenue growth has deepened because Facebook's fastest expansion is in users accessing the site on mobile devices, which command lower advertising rates, the paper said.
The challenge presented by mobile, which accounts for 600 million of Facebook's users, was underlined last week when Google shocked Wall Street with much lower profits than forecast, it added.