Claire Enders (pictured) said the explosion of smartphone and tablet use was causing a substantial "shift downwards" for print.
"We're going to see a very strong accelerated trend in print circulation declines in this country. It's going to be very difficult for the newsagents and the printers, combined with an increase in paper, ink and petrol costs," Enders told the FT Digital Media Conference in London today.
She said paying print subscribers were not being successfully converted into paying digital users: "They haven't been doing that. The economics of the transition [to digital] is quite challenging."
Enders added that she did not believe that consumer publishers would succeed in finding a suitable model for paid-for online content, unlike in business-to-business where the FT's metered access approach has proved popular.
"In the consumer end of the press we haven't seen any successes yet," she said. "In the consumer press it isn't going to work."
One publisher hoping to prove her wrong is the New York Times Company, which is preparing to launch a metered paywall.
Chairman and publisher Arthur Sulzberger said the hope was that 5-10 per cent of unique users to the site will pay for access beyond the free quota of stories, at a cost of between $6 and $12 a month.
He said the company was "spending so much time" finalising the move towards paid-for content had taken so long because it wanted to get it right.
Sulzberger added: "It's not going to solve all the problems of all the papers in the world but it is a significant new revenue stream. Most importantly you don't lose your voice in the community you don't lose your ad revenue.
"You are still allowing for people to engage with your journalism when they are not deep loyalists and you are going to make advertising dollars from that.
"The people who are going to pay are loyalists - welcome to real life."
Steven Brill, co-founder of digital publishing and sales company Press+ predicted that charging for online content at the New York Times would bring in between $80m and $110m a year in new revenue.