The Competition and Markets Authority says the media giant is also promising similar levels of investment as part of its planned takeover of Sky plc.
However, in the documents, which were put together by law firm Allen & Overy and published by the CMA, it added that 21st Century Fox considered the CMA's provisional findings "contained a number of material legal and factual errors". Fox also reiterated a previous proposal for "a commitment to Sky-branded news services in the United Kingdom for at least five years with similar levels of investment".
In a statement Fox wrote: "The combined effect of the Proposed Firewall Remedies is that there could be no circumstances in which, post-transaction, the MFT (Murdoch family trust) or members of the Murdoch family could influence, whether directly or indirectly, the editorial line or policy of Sky News".
The board will be made up of independent members with United Kingdom media experience and oversee any changes to the Sky News editorial guidelines, which Fox said had been amended to offer further safeguards giving the head of Sky News "complete control over editorial matters" and editorial staff.
Rupert Murdoch has committed to maintaining Sky News in the United Kingdom "for at least five years" as he looks to push through his bid to buy the 61 per cent of Sky he doesn't already own. "As one of the organization's founding shareholders, 21CF has been a supporter of Sky (including Sky News) since its origin".
Should the takeover proceed, Fox said in its submission that it would establish an independent board to outline the media organisation's editorial strategy and direction.
The British government had referred the takeover to the CMA for an in-depth probe last September owing to concerns about media plurality and broadcasting standards.
"Our view is that neither structural nor behavioral remedies proposed are an acceptable answer to the plurality concerns raised by the Fox takeover of Sky", the lawmakers said. It is not known whether Disney would commit to retaining the loss-making news channel if its acquisition of Fox goes through, however.
The Authority will make a final decision with a report submitted to Matthew Hancock, the Secretary of State, by 1st May. In particular, we suggest that the CMA should not go down the same path that has failed before: "undertakings given and broken, by the Murdochs".