James Foster has taken over as Essex captain following Mark Pettini's decision to stand down.
Former England wicketkeeper Foster was already leading the county in Twenty20 cricket but will now be in charge for all formats.
Batsman Pettini has struggled for runs this season and, with the pressure mounting over his position, he recently took a short break from the game.
The 26-year-old returned to the line-up for the Friends Provident t20 defeat to Sussex Sharks on June 29.
"I felt it was time for me to step down as Essex captain," Pettini explained on the official Essex website.
"We suffered a poor start to the Friends Provident t20 campaign and I wanted to be able to focus on my own game. I got to the point that I was exhausted and
I was under pressure with my batting.
"The team performances were, at that stage, not going to plan and personally I was struggling with the bat."
Pettini, who hit 59 from 38 deliveries against Sussex, added: "Hopefully in that game I showed the difference to my game without the pressures of being captain.
"The role is obviously very stressful and creates a lot of hard work, both on and off the pitch.
"Now I can focus on scoring runs across all formats of the game which will hopefully help us to have another successful season, with a chance of winning some major honours.
"It was an extremely tough decision to make."
Essex coach Paul Grayson believes the change of leadership could be of benefit to all concerned.
"James is obviously a well respected member of squad; he has done a great job with the Twenty20 captaincy," Grayson added.
"We want Mark to come back into the ranks and for him to be the player that he was.
"Anyone who was here for the game on Tuesday night would have seen he was really refreshed and focused, he did not appear to have any concerns and that is the way we want him to play for Essex."