Time Warner Inc., the world’s largest media company, reported an 80 percent increase in third-quarter earnings Wednesday and raised its stock repurchase program to $12.5 billion from $5 billion in an effort to meet shareholder demands to lift its slumping stock price.

The New York-based company, whose properties include the Warner Bros. Studios, HBO, CNN, a major cable TV company and Time magazine, posted net earnings of $897 million versus $499 million in the same period a year ago.

Per-share earnings came in at 19 cents compared with 11 cents a year ago. Revenues rose 6.1 percent to $10.54 billion from $9.94 billion.

The company also announced an increase in its share buyback program to $12.5 billion over the next 21 months, up from the previous level of $5 billion.

Time Warner’s shares rose 33 cents, or 1.9 percent, to close Wednesday at $17.90 on the New York Stock Exchange.