Craig Spearman is leaving Gloucestershire after eight seasons with the county.
The New Zealand batsman, 37, has reached an agreement to be released from the final year of his contract.
The highlight of his time with the county was his club record 341 in 2004, a score which eclipsed the previous best by WG Grace.
"I have had an immensely enjoyable eight years at Gloucestershire and I would like to thank my colleagues and the members for their wonderful support over the years," Spearman said.
"I will miss the club and wish them every success for the future."
Gloucestershire director of cricket John Bracewell added: "Craig has been an outstanding servant over a number of years - capturing a number of record breaking performances which will place him high in the status of great Gloucestershire batsmen and his experience will be missed.
"We wish Craig all the best as he pursues other endeavours."