Worcestershire have announced that chief executive Matt Rawnsley has left the club with immediate effect.
In a terse statement, the club offered its thanks to Rawnsley and said that the board "wish him every success in the future".
Club chairman Fanos Hira will handle club matters while the position is vacant, while the club's 'cricket steering group' will continue to take control of cricketing affairs.
The circumstances of Rawnsley's departure are unclear, though the club said that further comments would be made "in due course".
Since Rawnsley re-joined the club in March 2018, Worcestershire had won their maiden T20 Blast title in 2018, and again reached the final this season where they suffered a last-ball defeat to Essex.
But they only finished eighth in the Championship in 2019 having been tipped by most for a promotion challenge, which represented their worst finish since the introduction of two divisions in 2000.
Rawnsley also sat on the board of Birmingham Phoenix - the Edgbaston-based side in the Hundred - and was an advocate of the new competition. It is expected that his successor will replace him in that role too.