Dec 1 (Reuters) - AMC Networks Inc Thursday estimated it would incur $350 to $475 million in pre-tax charges related to its restructuring plan announced on Nov. 28, according to a regulatory filing.

The media company behind such hits as "The Walking Dead" and "Interview with the Vampire" adapted from the Anne Rice novel, said it would cut about 20% of its U.S. workforce as it adjusts to a decline in cable subscribers and a cooling economy.

Its chief executive, Christina Spade, stepped down this week after just three months on the job.

AMC Networks, with its namesake network, Sundance TV and BBC America, benefited from the growth in cable TV. Its dark dramas, including “Mad Men” and “Breaking Bad,” attracted viewers and critical acclaim.

It has struggled in a world dominated by much larger streaming players, such as Netflix Inc and Amazon.com.

MoffettNathanson analyst Robert Fishman wrote that, like other media companies, AMC has seen its lucrative television business decline even as it pivots to the more capital-intensive, less lucrative world of streaming.

“Unfortunately, there is no U-turn for any company here to move back into the old world,” Fishman wrote earlier this month.

Cord cutting and a gloomy advertising market have weighed on the company's business, with shares down 42% year to date. (Reporting by Dawn Chmielewski in Los Angeles; editing by Diane Craft, Stephen Coates and David Gregorio)