MediaNews today appointed one of its executives, David Butler (left), as executive editor of the Mercury News, replacing Carole Leigh Hutton (right), who has held the job for seven months. Butler, vice president for news for MediaNews in Denver, will take over in San Jose immediately.

The Merc did not say why Hutton was stepping down.

In an e-mail to the Merc staff, Hutton said she left with “jumbled emotions” but plans to remain in the Silicon Valley. “I look forward to watching as you continue to confront the challenges we’ve been tackling,” Hutton wrote.

She previously had been editor and publisher of the Detroit Free-Press. Publisher Jeff Kiel said in a statement: “Carole Leigh has been instrumental in leading the Mercury News’ efforts to understand how we can provide news and information in print and online that is central to readers’ lives.”

Butler, 57, will be responsible for all news and editorial-opinion operations. He also will maintain his role at MediaNews, coordinating the news and editorial activities of its 68 daily newspapers and Web sites. Before being named MediaNews’ vice president for news, Butler was editor and publisher of The Detroit News. Prior to that he was editor of the group’s Los Angeles Daily News, executive vice president for news for the Los Angeles Newspaper Group, and an editor or reporter at newspapers in Colorado, Connecticut, Florida, Kentucky and Illinois.

Butler and his wife, Kate Lee Butler, will move to the Silicon Valley from Denver. She is business development director of U.S. online newspapers for the AP. MediaNews chief executive Dean Singleton is chairman of the AP.