VIERA, Fla. — Jim Bowden’s final move as Washington Nationals general manager was his own resignation.

Bowden abruptly stepped down Sunday morning after four seasons, leaving under the cloud of a federal investigation into the skimming of signing bonuses given to Latin American prospects.

He has maintained his innocence in the matter, but said Sunday, ‘‘I’ve become a distraction.’’

‘‘It’s an emotional decision. It saddens me. But I feel it’s in the best interest of two of the things I love the most, and that’s the Washington Nationals and baseball,’’ added Bowden, who was Cincinnati’s GM in the 1990s.

Seated at a table with Nationals president Stan Kasten before a small contingent of reporters and team officials, Bowden read from a prepared statement, sometimes deviating from the script as he struggled to contain his emotions.

No replacement was immediately announced.

‘‘We’re not planning on missing a beat,’’ Kasten said. ‘‘Our staff has a meeting tomorrow morning, first thing. I’m not going to have anything to say to you about next steps for a while — later in the week.’’

Bowden is the only GM the Nationals have had since the franchise moved from Montreal to Washington before the 2005 season, overseeing a team that went 81-81 in that debut season but has been below .500 ever since.

Last season, the Nationals were a major league-worst 59-102.

‘‘It takes a lot of courage for (Bowden) to do that,’’ Washington manager Manny Acta said after Sunday’s 7-5 exhibition loss to Baltimore. ‘‘Is he perfect? No. But few are brighter and few work harder.’’

Bowden’s tenure with the club was marked by such moves as the trade for Alfonso Soriano, the failure to re-sign Soriano, free-agent busts such as Paul Lo Duca and reclamation projects such as Dmitri Young.