Liberty completed their $8 billion takeover on Monday and a subsequent filing to the US Securities and Exchange Commission (SEC) showed 86-year-old Ecclestone was offloading 950 599 shares.
The Series C Liberty Formula One common stock shares were trading at around $30.73 on Thursday.
Other associates of Ecclestone, including Martin Sorrell who is the chief executive of advertising agency WPP and served as an independent director of Formula One's parent company, are also cashing in.
A total of 1 357 700 of the Nasdaq-listed shares are being sold immediately.
Ecclestone, who was replaced by Chase Carey as chief executive on Monday, will retain a holding of 896 639 shares after the offer.
The prospectus, posted on the Liberty Media website, also revealed financial details about the series that had hitherto been kept confidential.
Formula One recorded total revenue of $1.7 billion for the year ended December 31, 2015, with the majority (primary revenue) derived from race promotion, broadcasting and sponsorship arrangements.
Gross profit in 2015 was $557 million, compared to $571 million in 2014.
The revenue from television rights agreements in 2015 represented 32.3 percent of the total.
