Mike Rizzo will assume day-to-day control of the Washington Nationals' major league operations after the sudden resignation of general manager Jim Bowden.

Team president Stan Kasten made the announcement Wednesday, but said he will have final say on personnel matters while the Nationals wait to permanently fill the GM vacancy.

"We've had enough instability in the last couple of weeks. I like stability," Kasten said. "I don't like interim titles, by nature, because they suggest instability. So I'd rather just keep things in place while we proceed _ especially since we have our functions down pretty well."

Rizzo has been an assistant GM and vice president of baseball operations since 2006. He came to Washington from the Arizona Diamondbacks, where he was praised for creating a minor league system that produced a number of talented prospects.

"I do know the major league team and I know the minor league system very well," Rizzo said. "The front-office team, we've been together for a long time. It's a very comfortable transition for me into new responsibilities and working with people I've grown accustomed to."

The 48-year-old Rizzo welcomed the opportunity to prove to Kasten that he's ready for the GM's role on a permanent basis.

"My goal has always been to be a major league general manager," he said. "As Stan said, we have a good feel for each other right now and we have a good group put together here with the Nationals."

Kasten said he's been fielding inquiries about the general manager's job since Bowden stepped down Sunday. Bowden has been linked to an FBI investigation of bonus money skimmed from Latin American prospects.

Kasten plans to conduct a widespread search for a replacement. Kasten left the team after meeting with reporters Wednesday, shortly after he learned of the death of his mother.

"We will get around to a search at the right time," Kasten said.

Asked how long before any permanent decisions would be made, Kasten replied: "It could be weeks, it could be months. I couldn't predict. ... But I don't feel any rush at all."

The rest of Washington's front-office team will remain in their current roles. Assistant general manager Bob Boone will continue to handle minor league operations, while Dana Brown will remain in charge of scouting.

Kasten and Rizzo have been working closely since Bowden's resignation, fielding trade offers and discussing how to improve the Nationals' roster. Kasten had said Monday he would be handling the general manager's role until a replacement was selected.

"It's been a hectic couple of weeks for us, but we've put a lot of turmoil behind us. Things have been operating so smoothly and comfortably that that's exactly how we're going to continue for the foreseeable future," Kasten said.

"A little bit of calming, rather than more change now, is what we need best."

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