(Adds Televisa confirmation, company details, share price, other background)
MEXICO CITY, Oct 26 (Reuters) - Emilio Azcarraga will step down as chief executive of Grupo Televisa but remain as chairman, the Mexican company said on Thursday, as the world's top Spanish-language content producer faces challenges with tougher competition and weak ad sales.
Televisa Vice President Alfonso de Angoitia and Chief Financial Officer Bernardo Gomez will take over as co-chief executives, Televisa said.
Azcarraga, the son of the Mexican media company's influential and politically powerful longtime boss, will step down as of Jan. 1, 2018, Televisa added.
The Wall Street Journal, which was first to report the news, said the decision for Azcarraga to step down was approved by the board on Thursday.
Televisa, which will report third-quarter results later on Thursday, has been contending with slowing ad sales and a global trend toward content delivered over the internet instead of traditional television.
Like its U.S. peers, Televisa is under pressure as younger viewers shun cable bundles in favor of less expensive streaming options including Netflix Inc, and as advertisers redirect spending to online ads.
Shares in Televisa, which has a reputation for wielding huge political power in Mexico, were up 1.5 percent at 91.60 pesos on Thursday.
This year, Televisa shares have risen around 5 percent, compared with a rise of more than 7.5 percent in the broader S&P/BMV IPC index.
Angoitia told investors on a conference call in July that the company had a difficult first half of the year.
"We're not pleased with the results," he said. (Reporting by Christine Murray and Gabriel Stargardter; Editing by Matthew Lewis)