Zduriencik failed to deliver the team's first playoff appearance since 2001.
Assistant general manager Jeff Kingston will assume interim general manger duties for the remainder of the season.
Mariners president Kevin Mather issued the following statement:
“We have reached the point when change of leadership of our baseball operations is needed for the Seattle Mariners to reach our goal of winning championships. We are very disappointed with the results this season, and are not satisfied with the current operation. The search for a permanent general manager will begin immediately, and while there is no deadline, we expect to have a new GM in place as soon as practical."
Zduriencik was hired by the Mariners in October 2008 after serving as an assistant general manager with the Milwaukee Brewers.
The Mariners have not made the playoffs since 2001 and never finished a season higher than third place in the division under Zduriencik's direction.
Entering Friday, Seattle sits 12 games behind the Houston Astros in the American League West division with a record of 59–69.
- Christopher Chavez