Kara Swisher and Walt Mossberg, the former editors of News Corp.’s AllThingsD, unveiled a site called Re/code on Thursday, taking on their old employer in technology news and conferences.

The site will be operated by a new media company named Revere Digital, with the backing of NBCUniversal and media executive Terry Semel, according to a statement today. As part of the agreement, Revere journalists will appear on CNBC, MSNBC, the “Today” show and other outlets owned by Comcast Corp.’s NBCUniversal.

Re/code faces an increasingly competitive market for technology coverage, including a fresh site from News Corp.’s Wall Street Journal. News Corp. is replacing AllThingsD with WSJD, which will have a similar combination of news and conferences. WSJD plans to host a global conference in Laguna Beach, California, in October.

“We made a strategic decision last year to invest heavily in technology coverage,” Wall Street Journal Editor-in-Chief Gerard Baker said yesterday in an online statement. “WSJD represents the first fruits of that investment. No topic is more important to our readers than tech.”

Swisher and Mossberg 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, people familiar with the matter said last month. The two editors couldn’t agree to terms with News Corp. to retain the AllThingsD brand, according to the people.

Conference Speakers

Swisher and Mossberg are serving as co-chief executive officers of Revere, which will include a global conference business. As part of the deal, the business-news channel CNBC will become a media partner for the conferences.

Its main event, called the Code Conference, will be held in May in Rancho Palos Verdes, California. The speakers include BlackBerry Ltd. CEO John Chen and incoming Qualcomm Inc. CEO Steve Mollenkopf. Comcast CEO Brian Roberts, whose company is backing the venture, also will appear at the event.

Semel, a former Warner Bros. executive and CEO of Yahoo! Inc., is investing in Revere through his firm Windsor Media.

Bloomberg LP, the parent of Bloomberg News, competes with News Corp. and CNBC in providing financial news and information.