AllThingsD editors Walt Mossberg and Kara Swisher, who are leaving News Corp. at the end of the year, have completed a deal with NBCUniversal for a news and conference business that will bring their current staff to a newly named website, according to people familiar with the matter.

Mossberg and Swisher will have majority control of the venture, with NBCUniversal and another unnamed investor together taking about a third of the business, according to one of the people, who asked not to be identified because the matter is still private. The new business tentatively plans to announce the agreement on Jan. 2, they said.

The deal provides NBCUniversal, owned by Comcast Corp., with a bigger entry into technology coverage and potentially gives the startup’s stories exposure on CNBC, NBC News and MSNBC. The test for Mossberg and Swisher, who co-manage AllThingsD’s news and conference operations, is whether they can duplicate the success they had building the original business — while also competing with former parent News Corp.

“It’s like they’re moving from one fast-moving train to another,” said Ken Doctor, a media analyst with Burlingame, California-based Outsell Inc. “It’s a good fit for Walt and Kara, and it has a lot of potential. NBC is one of the few that has reach and money and is newly appreciative of content.”

Ashley Huston, a spokeswoman for New York-based News Corp., declined to comment, as did Cameron Blanchard, a spokeswoman for NBCUniversal.

News Corp. Split

The two editors agreed to cut ties with News Corp. in September and sought investors for the new startup, which they valued at about $25 million to $35 million, two of the people said. AllThingsD was a profitable unit of News Corp., generating about $14 million in annual sales and about $5.5 million in profit, according to the people.

The main conference would sell out its 500-seat event at about $5,500 per ticket. AllThingsD also hosts other events focused on media, the mobile industry and China. Bloomberg News, part of Bloomberg LP, competes with News Corp., NBCUniversal’s CNBC and AllThingsD.

Mossberg and Swisher couldn’t agree to terms with News Corp. to retain the AllThingsD brand, according to two of the people. The startup will take most of the current AllThingsD staff, who will become employees of a new holding company, they said. That business will be called Revere Digital, named for the Revolutionary War hero Paul Revere, according to the people.

Mossberg and Swisher haven’t disclosed what the news website will be called.

Ad Revenue

The AllThingsD website brought in about $3 million to $4 million in annual advertising sales, though most of that revenue was tied to deals that run across News Corp.’s other sites, such as wsj.com, according to the people.

After building a following at the Wall Street Journal, Mossberg and Swisher started the AllThingsD conference business in 2003. They later added a news site, which became a major source of information on startups, media and the technology industry. The AllThingsD events frequently attracted top executives, including the late Steve Jobs, who rarely spoke at conferences when he ran Apple Inc.

“The question now is how fast NBC can help them build and grow that audience in the new venture,” Doctor said.