Sheryl Sandberg, Facebook's number two executive, has shed more than half her stake in the social networking company since its initial public offering less than two years ago, according to an analysis of recent regulatory filings.
The series of disposals, some of which were made to satisfy tax bills, are likely to add to persistent questions about whether Sandberg is eying an eventual departure from the company for a future in government or as head of another large company.
However, her name has yet to be closely linked to any senior corporate positions and she has denied any plans to compete for political office – most recently in January, when she said that politics was "not for me".
Also, even after the disposals, Ms Sandberg's stake worth about $1bn still makes her one of the largest individual investors in Facebook with a 0.5 per cent stake.
As chief operating officer, the former Google executive was brought in at a critical time in Facebook's development, when the company was first looking to ramp up its revenues and a young Mark Zuckerberg was still trying to find his feet.
The Facebook chief executive has since developed a greater management self-assurance and taken on many of the company's key decisions, for instance in his personal handling of deals such as the acquisitions of WhatsApp and Instagram.
Sandberg has frequently been talked of as a candidate for high office in Washington. A former chief of staff to Larry Summers at the time he was treasury secretary under Bill Clinton, she was said to have been considered for that position during the first Obama administration.
Sandberg has sold about 10m shares worth some $400m since Facebook made its stock market debut in May 2012, according to filings with the Securities and Exchange Commission. The sales were made under the "blind" trading plans that corporate executives use to spread their disposals out over a period of time, reducing the risk of being accused of trading on privileged information.
She also sold nearly 16m shares in late 2012 to settle a tax bill that fell due when restricted stock she had in the company vested to become ordinary shares.
Along with a number of other small disposals, that has taken Ms Sandberg's overall stake down to 17.2m shares, restricted stock units and options in the social networking company. At the time of the IPO, she held about 41m shares, most of them in the form of restricted stock units.
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