TOKYO — Sony Corp. and Fuji Television Network will announce today that they are joining Rupert Murdoch’s direct satellite broadcasting venture in Japan, JSkyB, as partners.The move will represent Sony’s entry into the broadcasting business, and Fuji TV will become the first terrestrial Japanese network to take part in a satellite venture. Murdoch, along with Sony’s president Nobuyuki Idei, Fuji TV president Hisashi Hieda, and Masayoshi Son, the president of Softbank Corp., will announce the deal at a press conference, JSkyB said. “We are delighted that Sony Corp. and Fuji Television Network will join our two founding shareholders — News Corp. and Softbank Corp. — to serve as new shareholders and management partners,” JSkyB said in a statement. Murdoch’s News Corp. and Softbank founded JSkyB, which will go into service with 150 channels next April, as equal partners. Sony and Fuji TV are expected to join the venture as equal partners. Sony has been a hardware provider for Japan’s two other satellite broadcasting platforms, PerfecTV and DirecTV. Sony’s announcement a few months ago that it will join JSkyB on the broadcasting end helped trigger a run on Sony shares that brought them to record highs on the Tokyo Stock Exchange. Having Fuji TV on board will be a boon for JSkyB. Murdoch has said he wants to have a local content provider in the satellite venture, and Fuji TV has one of the strongest libraries of sports, dramas and movies among Japan’s networks. Fuji TV will go public in the fall. It recently moved into a new headquarters on the Tokyo bayfront and is building digital studio facilities. Other companies that have been in talks with JSkyB include Walt Disney Co. and Japanese trading house Marubeni Corp. A Marubeni official said the company has been discussing the deal with JSkyB for several months. The trading house said it would like to buy into the satellite venture. Marubeni plans to starts a project to provide programming for satellite broadcasting platforms. Japanese media reported that Sony and Fuji TV will join News Corp. and Softbank as equal partners, with each company holding a 20% stake in JSkyB. Marubeni, Disney, advertising agency Dentsu Inc. and the Asahi Shimbun newspaper corporation may buy into JSkyB as lesser partners. At Murdoch’s last news conference in Tokyo on March 3, he and Son of Softbank said the two companies were bailing out TV Asahi and selling off the shares they had in the Japanese network. The two companies sold their 21.4% stake in TV Asahi to the Asahi Shimbun. Top brass at TV Asahi and the Asahi Shimbun were angered at the prospect of having a Murdoch representative sit on TV Asahi’s board of directors, which scuttled plans to use TV Asahi as a content provider for JSkyB. The other direct digital satellite broadcasters in Japan are PerfecTV, which started to service last year, and the Hughes Electronics Corp.’s DirecTV, which is set to start service around December of this year.