Pietersen said "I have as of this afternoon decided to stand down as England captain with immediate effect."
"Notwithstanding my resignation as England captain, I still fully intend to be a part of both England’s Test and one-day international squad to tour the West Indies next month and to do all I can to recapture the Ashes during the summer."
He added: "I am extremely sad and disappointed to have to relinquish the captaincy at such an early stage, especially in a crucial year for English cricket, in such circumstances and particularly when I feel that I have much more to offer the England team as captain."
"However, this decision will not affect my determination to continue playing international cricket for England, doing all I can to win matches for the team and supporting whoever captains the team in the future."