Leaders of two technology powerhouses are leaving the Walt Disney Co.’s board as their companies increasingly compete with the media giant for the attention of online viewers.

Facebook Chief Operating Officer Sheryl Sandberg and Twitter Chief Executive Jack Dorsey aren’t up for re-election when the company holds its annual shareholder meeting March 8, in Houston, Texas, according to a regulatory filing.

Given our evolving business and the businesses Ms. Sandberg and Mr. Dorsey are in, it has become increasingly difficult for them to avoid conflicts relating to Board matters, and they are not standing for re-election,” a Disney spokesperson said.

Disney plans to launch an ESPN-branded streaming service later this year, and a Disney-branded entertainment offering in 2019. Facebook, meanwhile, is investing heavily in programming for Facebook Watch, striking deals including one with ABC’s Scandal star, Kerry Washington, who’s launching an original series this year on the social media platform, and a live weekly show from WWE called the Mixed Match Challenge, a 12-episode series is pitting male and female stars from its Raw and SmackDown Live.

Twitter has expanded into live-streamed video content through partnerships with Major League Baseball, BuzzFeed and others.

Board members Robert Matschullat, former Seagram Co. executive, also will be departing the board because he has served for 15 years, the maximum tenure, and Orin C. Smith will depart because he has reached the retirement age of 74, Disney said. The board will take up the matter of filling Smith’s role as independent lead director when it meets after the annual meeting.

Disney previously announced that Safra Catz, Oracle Corp.’s co-chief executive, and Illumina Inc. CEO Francis deSouza, would join its board of directors. The elections are effective as of Feb. 1.

Disney also disclosed executive compensation in its proxy filing.

Chairman and CEO Bob Iger’s total compensation fell 17% from the prior year. He received $36.3 million in total compensation for the year ended Sept. 30, 2017, down from $43.9 million a year ago.