(Telecompaper) Investor Carl Icahn has abandoned his months-long campaign to get Apple to buy back additional portions of its stock, following news that a major advisory firm and investor would not offer support for the plan, reported CNN. In an open letter to Apple shareholders, Icahn said he agrees with ISS, an advisory firm, that Apple has already bought back a large amount of its stock, and there is not a need for more aggressive action. "While we are disappointed that last night ISS recommended against our proposal, we do not altogether disagree with their assessment," read the letter, which noted that Apple is on course to buy back USD 32 billion in shares during 2014, an amount that is USD 18 billion short of what Icahn was asking for. "In light of these actions, and ISS's recommendation, we see no reason to persist with our non-binding proposal, especially when the company is already so close to fulfilling our requested repurchase target," the letter said. New York City Comptroller, Scott Stringer, who controls investments in the city's pension plan and is a major investor in Apple, also disagrees with Icahn's buyback plan. Icahn has purchased more than USD 4 billion in Apple stock since summer 2013 and had been pushing the company to buy back additional stock and launch new products at a faster pace.