Mark Katches, The Oregonian/OregonLive's editor and vice president of content, is stepping down next month to take a new job as executive editor of the Tampa Bay Times.

Katches, 55, oversaw the Portland-based newsroom during the most explosive digital growth phase in its history. The newsroom has expanded its online audience more than 70 percent during the four years he has served as editor. The staff also has garnered numerous regional and national awards for investigative and narrative journalism.

"Mark is passionate about making a difference through quality, in-depth reporting," said John F. Maher, president of the Oregonian Media Group. "His contributions to our company and to our community will have a lasting effect. We wish him the very best."

Despite challenges facing most every newsroom in America, The Oregonian/OregonLive remains the state's biggest news organization. Its digital footprint is the largest in the Pacific Northwest. The newsroom has distinguished itself with more watchdog journalism, a video unit that earned six regional Emmy nominations this year, and a team of reporters that provides readers a constant feed of breaking news.

Katches came to Portland from the California-based nonprofit Center for Investigative Reporting in 2014 and encouraged deep dive journalism across the newsroom. That manifested itself in stories about dangerous levels of lead dust in the nation's national guard armories, an ongoing series of stories about troubles in Oregon's senior care facilities, and coverage that exposed how Portland Public Schools mishandled the case of an instructor who for decades had preyed upon teenage girls. He also championed narrative writing like the acclaimed "The Loneliest Polar Bear" about a hand-raised captive born bear.

"Serving as editor of this talented newsroom has been an incredible privilege," Katches said. "It's been so much fun watching these devoted journalists tell stories that have captured the heart of a community and have had resounding impact. I know the newsroom will be in excellent hands."

Maher has named Therese Bottomly, a 35-year veteran of the newsroom, as interim editor. Bottomly has been serving as senior director of news.

"Therese is a capable leader and respected journalist who is intimately familiar with our ongoing operations as well as our long-term investigative work," Maher said. "I'm confident our reporting team will excel under her direction."

Katches' last day as editor in Portland will be Aug. 3.