HarperCollins president and chief executive Jane Friedman stepped down from her post, becoming the second publishing CEO to resign this month, on the background of increasing pressure on the industry.

The departure of Ms. Friedman, which surprised colleagues, comes shortly after the resignation of Peter W. Olson, the chief executive of Random House. Olson, who held the job since 1998, stepped down following losses at the unit of Germany’s Bertelsmann AG caused by a wider slowdown in book sales.

Ms. Friedman will be replaced by Brian Murray, group president of HarperCollins, the news corporation, owned by Rupert Mudoch's News Corp., announced in a statement.

"We are enormously grateful for her contributions over the past 10 years and understand her desire to seek new challenges at this point in her career," Murdoch said in the statement that was released late Wednesday.

Ms. Friedman started overseeing HarperCollins’ book publishing in 1997, after she had previously served as executive vice president at Random House Inc. and the Knopf Publishing Group. She also worked as a publisher of Vintage Books and was founder and president of Random House Audio Publishing.

According to the Associated Press, she described her 10 years at HarperCollins as “far and away the most rewarding of my career” and she admitted the decision to step down was a difficult one to make.

Murray, 41, has been president of HarperCollins since July 2007. He held several positions in the General Books Group before 2001, when he was named chief executive of HarperCollins Australia/New Zealand.

After was named to replace Ms. Friedman, Murray expressed his enthusiasm to work with his colleagues, to “invest in and grow our publishing businesses around the world.”