The transactions follow the end of lockup periods for shares sold in the Menlo Park, California-based company's initial public offering in May. The stock has tumbled 23 percent since the $16 billion sale, the biggest IPO for an internet company.
Sandberg has a net worth of about $500 million, according to Bloomberg Billionaires. She owned 1.65 percent of Facebook following the Jan. 3 sales, according to data compiled by Bloomberg. The internet company rose 2.3 percent to $29.42 in New York trading Monday.