Pietersen, who was part of England's Twenty20 World Cup winning side, lives in London with his wife and baby son and wants to play for a county closer to home.
"Given England's critical dependence on KP (Pietersen) in all forms of cricket, we have not seen anything like as much of him as we would have liked over the past six years," Rod Bransgrove, chairman of Hampshire Cricket said in the statement.
"He remains, however, a fantastic player and we wish him continued success wherever he plays."
Pietersen, who joined Hampshire from Nottinghamshire after the 2004 season, has played only seven County Championship matches for the club.
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