Media Moghul Rupert Murdoch is finding it harder than expected to introduce "pay walls", a business model to charge readers for browsing his newspaper websites in a bid to shore up revenue for the struggling print media.

Newspapers are struggling with plunging print advertising revenue, steadily declining circulation and the migration of readers to free news online.

Murdoch, who controls the Times, the Sun, the New York Post and the Australian, had previously outlined plans to erect pay walls around his vast newspaper empire by the end of News Corp.'s current fiscal year in June but he indicated that was now unlikely.

News Corp. chairman and chief executive Murdoch admitted last night that the schedule was slipping. "I wouldn't promise that we're going to meet that date," he was quoted as saying by the Guardian newspaper on Thursday.

He declined to comment on the reasons. "It's a work in progress and there's a huge amount of work going on," Murdoch said in the report by the British daily.

A plunge in Murdoch's newspaper revenue was checked in the first quarter by strong results from News Corp.'s movie, cable television and book publishing divisions as the company posted an 11 percent rise in quarterly net profit, the report said.

Operating income soared 56 percent in the film division to 391 million dollars largely on the strength of 20th Century Fox's "Ice Age: Dawn of the Dinosaurs," which has grossed more than 880 million dollars at the box office, the report said.