New York—New York Times Co. President-CEO Janet L. Robinson will leave her post at the end of the year, according to a story posted on the company's Media Decoder blog. Robinson, who has been CEO since 2004, announced her pending departure in an email to the company's staff. New York Times Co. Chairman Arthur O. Sulzberger Jr. will act as CEO while the company searches for a successor to Robinson, according to the Media Decoder story. Robinson has presided over a particularly difficult period for the company and for the newspaper industry in general, which as a whole has seen advertising revenue decline for 21 straight quarters, according to figures from the Newspaper Association of America. The Media Decoder story said the company may search in the technology sector for a chief executive. Its flagship newspaper, The New York Times, recently introduced a metered model pay wall on its website that boosted the newspaper's total digital subscribers to 380,003 as of Sept. 30, according to Audit Bureau of Circulations figures. That was a fourfold increase compared with the end of March. Martin Nisenholtz, New York Times Co.'s senior VP-digital operations, last month announced plans to retire at the end of the year. Ken Doctor, an analyst for Outsell Inc., gave Robinson credit for seeing the New York Times Co. through a difficult period and putting it in a "relatively stable" position. "In 2011 they benefited more than any other news organization from the two biggest trends in the industry: charging for digital access and the arrival of the tablet," Doctor said.