NEW YORK -- Facebook's user base and revenue grew more slowly than expected in the second quarter as the company grappled with privacy issues, sending its stock tumbling after hours.

While it was the company's first full quarter following the Cambridge Analytica privacy scandal, analysts attributed the user growth shortfall largely to European privacy rules that went into effect in May.

Facebook had 2.23 billion monthly users as of June 30, up 11 per cent from a year earlier. Analysts were expecting 2.25 billion, according to FactSet.

The company earned $5.1 billion, or $1.74 per share, up 31 per cent and above analysts' estimates of $1.71.

But revenue -- up 42 per cent to $13.23 billion-- was slightly below the $13.34 that Wall Street was expecting.

Facebook's shares fell 7.6 per cent after-hours after closing at $217.50.