SAN FRANCISCO - Activist investor Carl Icahn is seeking the support of Apple shareholders as he tries to pressure the iPhone maker into spending more of its cash to buy back the company's stock.

Icahn fired the latest volley in his two-month-old crusade with a Wednesday disclosure that he has submitted a proposal to Apple Inc. that would enable the company's shareholders to vote on his ideas early next year. The announcement came on Icahn's own Twitter account and in an interview with Time magazine.

The attempt to gather more allies for Icahn's cause could set up a showdown between an acerbic billionaire and one of the world's most powerful companies.

But this battle seems unlikely to be as acrimonious as the many other attacks that Icahn has led on corporate boards that haven't acceded to his wishes after he has bought large stakes in their companies.

As he has in previous public statements, Icahn used his Time interview to express his admiration for Apple CEO Tim Cook, one of the eight directors on the company's board.

"Tim Cook is doing a good job with the business," Icahn told Time. "I think he's good whether he does what I want or not." The comments were made as part of a Time story that hails Icahn as "the most important investor in America" on the magazine's cover.

In another sign that Icahn is trying to maintain a cordial relationship with Apple even as he pesters the company, he made his proposal in a "precatory" form that makes it nonbinding even if a majority of shareholders vote for it. Nevertheless, Apple's board could face a backlash if it ignored the will of shareholders, even on a nonbinding measure.

Icahn, 77, didn't respond to a request for comment. He has been pushing Apple to spend $150 billion buying back its own stock since hosting Cook at a dinner in his New York apartment in late September. That meeting came after Icahn notified Apple that he had been accumulating stock in the company because he believes the shares are undervalued.

In his Wednesday tweet, Icahn said he is no longer pressing for Apple to spend $150 billion buying back its stock. He didn't specify a new target amount.

In his last public disclosure made in late October, Icahn said he owned 4.7 million Apple shares, or less than 1 percent of the company's stock.

Apple confirmed it has received Icahn's proposal, but didn't reveal anything about its content or whether it met the criteria to be included on the agenda of the company's annual meeting. The Cupertino, Calif., company hasn't set the date for the meeting yet, but it is usually held in late February.

"As part of our regular review process, we are once again actively seeking our shareholders' input on our program, and as we said in October, the management team and our board are engaged in an ongoing discussion about it which is thoughtful and deliberate," Apple spokesman Steve Dowling said. He said the board will announce any changes to its plans for its $147 billion cash hoard early next year.

Under pressure from other shareholders earlier this year, Apple agreed to spend $60 billion buying back its stock. That is in addition to about $40 billion in dividend payments that Apple expects to distribute to shareholders during the next three years.

As of late September, Apple had exhausted $23 billion of its budget for buying back its shares.

Apple's stock fell $1.32 Wednesday to close at $565. The shares have gained 6 percent this year. That lags the Standard & Poor's 500 index, which has risen 26 percent.