Durham batsman David Bedingham has agreed a new contract which will last to the end of the 2025 season.
The South African, 27, is the leading run-scorer in this summer's County Championship with 945, including a career-best 257 against Derbyshire.
He also scored a combined 590 runs in the T20 Blast and One-Day Cup.
"We all look forward to seeing David play a key part in our team's success during the next few years," said director of cricket Marcus North.
Meanwhile, Durham have released batsman Jack Burnham with immediate effect so he can "explore other opportunities".
The 24-year-old scored 357 runs in 10 Championship appearances this season, and also played twice in the T20 Blast.