In an interview with The Irish Sunday Times, Denis O'Brien, the company's second biggest shareholder, told the newspaper that it could go into "examinership" – a situation similar to the American Chapter 11 bankruptcy protection.
When asked about the possibility, he told the newspaper "We'll have to consider it".
O'Brien, branded a "troublesome shareholder" in some quarters, also maintained that he would block any attempted sale of the INM's South African advertising division, INM Outdoor.
The company is in the process of offloading subsidiaries in order to raise funds and reportedly received a £100m bid for INM Outdoor last week.
But O'Brien said: "I'm against it. South Africa has a hell of a good media market. The earnings in the outdoor business are growing at 20% a year. It's a great business. It doubles in four years."
Last week INM made just over £13m selling its 18% stake in gaming business Cashcade.
O'Brien holds a 26% stake in the publisher, bettered only by its creator Tony O'Reilly. The two are in dispute with each other over the way forward for the publisher, O'Brien demanding it sell its loss-making UK titles The Independent and The Independent on Sunday.
