Manohar’s decision comes after only eight months in office although the resignation is yet to be officially accepted by the game’s world governing body.
The 59-year-old was elected unopposed as the ICC’s first independent chairman last year. His two-year term was supposed to end in May 2018.
The former Board of Control for Cricket in India (BCCI) President sent a copy of his resignation letter to ICC CEO Dave Richardson on Wednesday.
“I have tried to do my best and have tried to be fair and impartial in deciding matters in the functioning of the board and in matters related to Member Boards along with the able support of all directors.
“However, for personal reasons it is not possible for me to hold the august office of ICC chairman and hence I am tendering my resignation as Chairman with immediate effect,” Manohar said in the letter.
“I take this opportunity to thank all the Directors, the Management and staff of ICC for supporting me wholeheartedly. I wish the ICC all the very best and hope it achieves greater heights in future.”
The first ICC chief not affiliated to any of its member boards, Manohar took over the post from N. Srinivasan in May last year after giving up his position of BCCI president.
Since then, he has tried to curb the disproportionate amount of power wielded by the BCCI, Cricket Australia (CA) and the England Cricket Board (ECB).
The ICC had passed in principle a new constitution last month that corrected some of the imbalance in influence and financial power of the BCCI, CA and ECB.
A final call on the new constitution was to be taken at the next round of meetings by the ICC board’s next month.