SAN FRANCISCO — Activist investor Carl Icahn thinks Apple Inc. should be doing more to revive its stock price, and he wants to help CEO Tim Cook with the resuscitation.
Icahn spoke out Tuesday on Twitter, saying he had acquired a large but unspecified stake in Apple and that he had a ‘‘nice conversation’’ with Cook about his belief the maker of iPhones and iPads should be using more of its $147 billion in cash to buy back its own stock.
An Apple spokesman described the discussion as positive but declined to elaborate.
In April, Apple pledged to spend $60 billion buying back stock through the end of 2015 as a way to return some of its cash to shareholders. About $18 billion had been spent through June 29. Apple also plans to dole out more than $10 billion in dividends each year.
Icahn thinks Apple should pour more money into its stock because he believes the shares are worth more than most investors believe. Despite a recent upturn that has reestablished Apple as the world’s most valuable company, the stock is 30 percent below its peak of $705.07, reached 11 months ago.
Investors began snapping up Apple’s shares on the hope the company might be forced to take steps to appease Icahn or risk the billionaire threatening an attempt to overthrow Apple’s board.
The stock surged $22.21, or nearly 5 percent, to finish at $489.87 — its highest closing price in nearly seven months. Icahn told The Wall Street Journal the stock could soon be worth $625 a share if Apple buys more of it back.
Icahn, 77, has been locked in a bitter battle with Dell Inc. as he tries to stop the slumping personal computer maker from selling itself to founder Michael Dell — a CEO who Icahn thinks should be fired. Using a 9 percent stake in Dell as leverage, Icahn has been leading a stockholder mutiny that led Michael Dell and Silver Lake Partners to raise their initial offer of $24.4 billion to $24.8 billion.
Icahn is fighting in court for the right to hold a vote to replace the company’s board.
Apple’s stock has slumped largely because growth has slowed, while earnings have been squeezed by tougher competition in the smartphone and tablet computer markets.
Investors also have been disappointed by Apple’s inability to unveil a breakthrough product since Cook succeeded Steve Jobs as chief executive nearly two years ago. Jobs died in October 2011, shortly after anointing Cook as his replacement.