Activist investor Carl Icahn waved the white flag Monday in his high-profile campaign to prod Apple into buying back $50 billion worth of stock. He is now voicing support for the tech giant's "aggressive" moves to buy back shares.
His statement came a day after a proxy advisory firm recommended that company's shareholders vote against Icahn's plan. Icahn had been agitating for months, pressing Apple to spend more of its cash pile while simultaneously adding to his own positions
In a letter, the billionaire said while he was "disappointed" that shareholder firm ISS recommended that Apple shareholders vote against his plan, he saw "no reason to persist with our non-binding proposal, particularly as the company is already so close to fulfilling our requested repurchase target."
(Read more: Carl Icahn buys $500 million more Apple, presses harder for buyback)
Apple has been in Icahn's crosshairs for months. Since late summer, the two have publicly sparred over his plan to boost the tech giant's wobbly share price by using its $160 billion in excess cash to repurchase shares. Icahn recently disclosed that he owned more than $3 billion of Apple stock, and that he intended to keep buying.
In recent weeks, Icahn—notorious for his battles with other fund managers and major companies—has voiced support for Apple CEO Tim Cook's strategic efforts.
"As Tim Cook describes them, these recent actions taken by the company to repurchase shares have been both 'opportunistic' and 'aggressive' and we are supportive," Icahn said in his letter.
Since hitting an all-time high above $705 in 2012, the company's stock has been buffeted by questions about whether Apple can compete in an increasingly tough marketplace for consumer technology.
Icahn said he was now "extremely excited about Apple's future."
—By CNBC's Javier David.