Facebook shares are expected to fall further this week after its chief operating officer Sheryl Sandberg and two other senior executives sold shares worth millions of dollars.
The sales are the first by Facebook's senior management following the end of restrictions preventing employees selling their shares which were imposed when Facebook initially floated in May.
According to Reuters, a filing with US financial regulators the SEC shows that Sandberg netted about $7.4 million (£4.7 million) by selling roughly 353,000 Facebook shares on 31 October. The filing also shows that Sandberg still owns roughly 20 million vested shares of Facebook stock.
Two other Facebook executives, general counsel Theodore Ullyot and accounting chief David Spillane, also sold millions of dollars worth of shares last week.
Since its landmark flotation in May, where Facebook became the only US company to enter the market at a value of more than $100 billion (£62 billion), the social network's share price has plunged as much as 50 per cent from $38 to today's $21.
There are concerns that with the end of restrictions, employees selling stocks will be a fresh blow for Facebook's fragile share price.
Roughly 230 million shares of Facebook became eligible for trading this week, with another 800 million shares eligible by mid-November.
The social network's 28-year-old founder and chief executive, Mark Zuckerberg, has said he will not sell any shares before September 2013.
Image credit: Flickr (World Economic Forum)