For years, tech billionaire Pierre M. Omidyar has been experimenting with ways to promote serious journalism, searching for the proper media platform to support with the fortune he earned as the founder of eBay. He has made grants to independent media outlets in Africa and government watchdog groups in the United States. In a more direct effort, he created a news website in Hawaii.

Then last summer, The Washington Post came calling in its pursuit of a buyer. The Graham family ended up selling The Post to a different tech billionaire, Jeffrey P. Bezos of Amazon. But the experience, Omidyar wrote on his blog today, “got me thinking about what kind of social impact could be created if a similar investment was made in something entirely new, built from the ground up.”

Omidyar also confirmed that he would be personally financing just such a new “mass media” venture, where he will be joined by journalist Glenn Greenwald of The Guardian, the British daily. Greenwald gained notoriety this summer when he reported on the revelations about National Security Agency surveillance contained in papers leaked by Edward J. Snowden.

The details of the new media organization are vague at this point. “I don’t yet know how or when it will be rolled out, or what it will look like,” Omidyar wrote.

What is clear is that Greenwald will be there, and he is expected to be joined by Laura Poitras, the documentary filmmaker who was the crucial conduit between Snowden and Greenwald.

Omidyar — who declined an interview request but released a statement and spoke to New York University journalism professor Jay Rosen — describes a happy coincidence: Just as he was looking to start his project, Greenwald and Poitras, along with the reporter and author Jeremy Scahill, “were already on a path to create an online space to support independent journalists.”

“We had a lot of overlap in terms of our ideas, and decided to join forces,” he wrote.

Rosen, on his blog, outlined some of Omidyar’s thinking: While Greenwald, Poitras and Scahill have focused on national security and U.S. foreign policy, the new project will be of more general interest. Rosen, paraphrasing Omidyar, writes that the project would not be a niche product, and that it would cover sports, business, entertainment and technology.