The Journal quotes sources as saying Social Capital Hedosophia Holdings (SPAC) is planning to invest $US800 million in Virgin Galactic for a 49 percent stake.
Virgin Galactic will become the first publicly-traded company dedicated to human spaceflight.
"Having got to know Chamath and Adam over the past few months, I have no doubt that we will be better together and am delighted they are becoming such important partners on our unbelievable journey".
Social Capital, led by former Facebook executive Chamath Palihapitiya, has raised $800m of cash to take a 49pc share.
"Together we will make our dreams reality".
Virgin Galactic was founded in 2004, two years later than SpaceX, and became the first company that focused on space tourism and the launch of small satellites into orbit.
In February, the company took a step closer to its goal of suborbital flights for space tourists when its rocket plane soared to the edge of space with a test passenger for the first time.
(AMZN.O) founder Jeff Bezos and Tesla Inc.'s (TSLA.O) Elon Musk, who are racing to send customers into space.
Branson has already invested more than $1.0 billion in the project since 2004, while a similar proposed Saudi capital injection was suspended past year following the killing of journalist Jamal Khashoggi.
Branson earlier this year announced that the Galactic's development and testing program had advanced sufficiently to move staff and space vehicles from the test site in Mojave, California, to the commercial headquarters, dubbed Spaceport America, in New Mexico.
A 90-minute flight, which allows passengers to experience a few minutes of weightlessness, costs about $250,000.
"Great progress in our test flight program means that we are on track for our handsome spaceship to begin commercial service", Branson said in Tuesday's statement.
To date VG has space tourism reservations from more than 600 people across 60 countries, earning it about $80 million in paid deposits and $120 million in potential revenues, the group said Tuesday.