Essex captain and wicketkeeper James Foster has been given permission to hold talks with Hampshire after they made a formal approach for him.
Foster, 31, has scored 8,976 first-class runs in his 11-year career.
Essex chief executive David East said: "We have offered James an extended contract and very much want him to carry on playing for us.
"He has been with Essex for his entire professional career. It would be hugely disappointing if he was to leave."
Head coach Paul Grayson added: "We want him to stay but we have given Hampshire an early opportunity to speak with James so we can understand as soon as possible where we are with this.
"We see him as an integral part of our club and strongly feel we have made him a good offer to remain at Essex.
"We clearly do not want to lose his services and want him to remain with us until the end of his career, but the decision is now for him to make."
Foster played seven Tests and 11 one-day internationals between 2001 and 2002, when he was seen as England's possible long-term successor to Alec Stewart behind the stumps.
He was then recalled by England for the World Twenty20 tournament in 2009, playing in all five games, but has not featured for his country since then.