Shares in Facebook fell sharply in after-hours trading Thursday, despite the social network giant's posting of an adjusted quarterly profit of 12 cents per share that matched analysts' forecasts in its first earnings report as a public company.

The earnings were what analysts, on average, had expected.

Its revenue grew 32 per cent to $1.18 billion US from $895 million a year ago.

That was slightly better than the consensus forecast of $1.16 billion, according to a survey by FactSet. In all of 2011, it had net income of $1 billion and revenue of $3.71 billion, according to regulatory filings.

Facebook reported after the market close Thursday.

In after-hours trading, its shares initially rose but soon reversed direction and were down $2.74, or more than 10 per cent, to $24.10. The decline means Facebook's stock will most likely open at its lowest level since going public.

"Growth is still at the low end of acceptable," independent technology analyst Carmi Levy told CBC News. "We still don't know whether or not this is a one-trick pony, or if Facebook really has a plan to drive consistent growth quarter after quarter."

Ad revenue totals $992M

The company said it booked a net loss of $157 million, or eight cents per share, in the April-June period after factoring in stock compensation expenses following its IPO. That compares with earnings of $240 million, or 11 cents per share, in the second quarter a year ago.

Overall, Facebook said its revenue from advertising totalled $992 million, representing 84 per cent of total revenue and a 28 per cent increase from the same quarter last year. It did not say what percentage came from mobile.

Facebook said it had 955 million active monthly users as of June 30, up 29 per cent from a year earlier.

After months of hoopla leading up to its $38-a-share IPO on May 18, Facebook saw its stock land with a thud, its deb