The loss-making German broadcaster is in breach of its lending covenants and needs to raise the cash to see it through to profitability.
If other investors, including Silvio Berlusconi's Mediaset, do not back the €450m cash call then News Corp could increase its stake.
News Corp has said it would only back refinancing if Bafin, the German market regulator, waived rules demanding a full takeover offer when an investor's stake tops 30%.
In the first stage of fundraising, Premier will sell 10.2m shares for at least €3.19 a share in January next year. News Corp will buy at least €25m in new equity, as long as its Premier stake does not thereby rise above 29.9%.
If Bafin agrees to News Corp's demand and waives rules demanding a full takeover, Premier will issue an unspecified number of new shares to bring new equity up to €450m.
News Corp will act as a buyer of last resort for this transaction if not enough other shareholders come forward to buy the new equity.
If this occurs, News Corp could raise its stake to anywhere between 40% and 70%, depending on the price of the rights issue and demand from other shareholders, according to sources quoted by the Financial Times.
News Corp's decision to underwrite Premiere's refinancing is expected to persuade other shareholders to take part.
This article was first published on brandrepublic.com