England opening batsman Keaton Jennings is to leave Durham and join Lancashire on a four-year contract.
The 25-year-old left-hander has been with the north-east county since 2012.
Jennings hit 112 on his Test debut in India last winter, but lost his place this summer after a run of low scores.
“It’s a fantastic opportunity for me to play Division One cricket at a Test match ground for a club, like Lancashire, with such a great history and tradition,” Jennings said.
“I have been hugely impressed by the vision for the future and playing a part in that alongside some hugely talented individuals and strong leaders.”
South Africa-born Jennings was a member of the Durham side that won the County Championship in 2013 and One-Day Cup the following year.
But he is is the third player to announce he is leaving the club at the end of the season, following Graham Onions and Paul Coughlin, the latter having agreed a three-year contract with Nottinghamshire.
“I have been hugely impressed by his professionalism and courtesy through what has been a very difficult decision for him,” chairman Sir Ian Botham told the club website.
Prior to Durham’s current game against Worcestershire, Jennings had scored 461 Championship runs this season at an average of 27, well below his first-class career average of 46.
However, Lancashire head coach Glen Chapple said he would be a “fantastic addition” to their squad in all forms of the game.
“I am very pleased Keaton has signed for Lancashire as I know there were other counties chasing his signature,” he added.
“He’s exactly the type of character and player I feel will add strength and depth to our squad.”
Jennings will find out on Wednesday whether he has been selected for England’s winter tour to Australia.
He said that despite being “career driven”, the decision to leave Durham had been “agonisingly difficult”.
“My heartfelt gratitude goes to Durham for the opportunities, support and guidance in enabling me to follow my dream of playing cricket in England,” he continued.
“Everyone in the north has become, and will remain, “family” to me.”