LONDON — Britain’s media and political landscape shifted Thursday as the powerful Murdoch family summarily announced plans to shut down the disgraced mass-circulation tabloid at the center of a deepening scandal over journalistic malfeasance, and arrest seemed imminent for the paper’s once politically influential former editor.

The decision by Rupert Murdoch’s media conglomerate, the News Corporation, to close the paper, The News of the World, seemed to be a calculated move to help protect Mr. Murdoch’s proposed $12 billion takeover of the pay-television company British Sky Broadcasting. But it hardly put an end to the uproar, or to Mr. Murdoch’s connection to it.

The scandal exposes a web of relationships between the Murdochs’ empire on the one hand and the police and politicians on the other. And it poses new challenges for Mr. Murdoch, a media tycoon who has at times seemed to hold much of Britain’s political establishment in thrall, cultivating connections to both Labour and Conservative governments and using the prospect of his support — or its withdrawal — to help drive his political agenda.