ATLANTA -- The Atlanta Braves say John Coppolella has resigned as general manager after it was learned that he was the target of a Major League Baseball investigation into a violation of rules in the international player market.

Braves president John Hart will take over GM duties while the team searches for a new one.

In a statement Monday, the Braves said, "the resignation comes as a result of a breach of Major League Baseball rules regarding the international player market." Hart said the Braves will give MLB their full co-operation during the probe.

An MLB spokesman would not provide details on an ongoing investigation.

The Braves, who finished 72-90 this year, have been very active in the international market in recent years.

Coppolella was promoted to GM after the 2015 season.