NEW YORK – Time Warner Inc. said Wednesday that net income grew 51 percent in the last three months of 2012 even as revenue was largely unchanged. Rising fees from cable and satellite companies and higher ad revenue at the TV networks offset revenue declines at the movie studio and magazine businesses.

The company also announced a dividend increase and a new plan to buy back shares. Its stock jumped to its highest level in more than a decade.

The television networks business drove the quarter's performance as revenue there grew 5 percent, offsetting declines elsewhere. The Warner Bros. studio business had a weaker release lineup in the most recent quarter, though it managed to report an operating profit with an emphasis on higher-profit TV production. The Time Inc. magazine business, the smallest of the three, has announced layoffs to reflect reduced demand for print editions.