Issuing a formal announcement, he said he had taken the decision after considering "the totality of this matter and the present political situation".
Kalam, who was propped up by Trinamool as a nominee for the Presidential poll to be held on July 19, said, "though I have never aspired to serve another term or shown interest in contesting the elections", Mamata Banerjee and other political parties "wanted me" to be the candidate.
"Many, many citizens have also expressed the same wish. It only reflects their love and affection for me and the aspiration of the people. I am really overwhelmed by this support," his statement said.
"This being their wish, I respect it. I want to thank them for the trust they have in me," he said, adding, "I have considered the totality of this matter and the present political situation, and decided not to contest the Presidential election 2012."
After Mamata pushed his candidature, breaking ranks with UPA over the issue, BJP also tried hard to persuade him to contest as Opposition's common candidate against Mukherjee.
BJP leader L K Advani called him thrice and sent his close aide Sudheendra Kulkarni twice to convince him. However, he made clear to Advani that his "conscience" is not permitting him to contest, sources said. (MORE)