• Sir Richard Branson sold more than $150 million worth of the company's stock over the past three days, a securities filing on Wednesday revealed.
• Branson, the founder of Virgin Galactic, took the company public through a SPAC merger with Chamath Palihapitiya's firm in 2019.
• Branson's sale comes a month after Palihapitiya sold his remaining personal stake in the company.

Sir Richard Branson, the founder of Virgin Galactic who helped take the company public in 2019, sold more than $150 million worth of the company's stock over the past three days, a securities filing on Wednesday revealed.

Branson, and four entities he controls including Virgin Group, sold 5,584,000 shares of Virgin Galactic between April 12 and 14. The shares were worth $150.3 million, sold at prices between $26.85 and $28.73.

Virgin shares closed Wednesday at $26.68, up 12% for the year.

Branson's sale comes a month after Virgin Galactic Chairman Chamath Palihapitiya sold his remaining personal stake in the company. Palihapitiya told CNBC at the time that he plans to redirect the sale "into a large investment I am making towards fighting climate change," adding that he remains "as dedicated as ever to Virgin Galactic's team, mission and prospects."

Last year, as the COVID-19 pandemic damaged Virgin Group's leisure and travel businesses, Branson sold about $500 million of his stake in Virgin Galactic. A Virgin Group spokesperson, in a statement to CNBC, said this week's sale is for the same purpose.

"Virgin intends to use the net proceeds from this sale to support its portfolio of global leisure, holiday and travel businesses that continue to be affected by the unprecedented impact of COVID-19, in addition to supporting the development and growth of new and existing businesses," Virgin Group said.

Virgin Group remains the largest shareholder in Virgin Galactic, with a 24% stake.

The space tourism company is working to complete development of the spacecraft that it plans to use to fly people to the edge of space and back. Virgin Galactic suffered a setback in December, when electromagnetic interference caused an early abort of its most recent spaceflight attempt – with the next attempt expected in May.

The development delays have pushed back Virgin Galactic's planned debut of its space tourism service, with CEO Michael Colglazier saying the company does not expect to begin flying commercial flights until early 2022. Virgin Galactic expects to fly four more spaceflight tests with its "VSS Unity" spacecraft, including flying Branson this summer.

Last month Virgin Galactic rolled out "VSS Imagine," the second spacecraft in its fleet, and the first of its next-generation class of vehicles.

"For us to make the business start to scale, at the places that we're aspiring towards, we need two things: We need many more ships than we have right now and we also need the ships that we bring forward to be built in a way that they're able to be maintained in a way that we can have much quicker [turnaround times between flights] than what we have with Unity," Colglazier told CNBC in March.