The two will take a 50% stake each in Consolidated Media, which owns 25% of pay-TV provider Foxtel, 27% of online job site Seek and 25% percent of PBL Media, which owns Nine Network (Australian free to air TV station Channel Nine), and publishing group ACP.
ACP in the UK owns Best, Reveal, and Real People as part of its ACP Natmags joint venture with the National Magazine Company.
It was also reported that the deal would put Lachlan in a strong position to take control of Nine Network when CVC Asia Pacific, the private equity firm that owns the remaining 75% sells up.
The deal would mark Lachlan's first major move since he exited father Rupert Murdoch's business two years ago.
It marks the second time the two heirs have teamed up after the ill-fated telecoms venture One.Tel in 2001, which collapsed with hundreds of millions of dollars in debt and in the end cost shareholders and family A$1bn.
The deal comes after James reorganised the business of his late father, Kerry Packer, dividing the media and gambling divisions in two businesses to build up the gaming operations.
Reports say that Lachlan Murdoch will become chairman of Consolidated Media.
Although Lachlan remains a director of News Corporation, he told The Australian, owned by Murdoch, that the planned deal was entirely his own: "This is completely my own transaction. This is nothing to do with News Limited or, for that matter, News Corporation."