Jack Dorsey, the company’s co-founder and chairman, will serve as interim chief executive while the board searches for a permanent successor.
The change is effective July 1. Twitter shares were up more than 7 percent in after-hours trading immediately after the news was announced.
Since Twitter’s debut as a public company in 2013, Mr. Costolo has repeatedly disappointed Wall Street as the company struggled to attract new users, refine its products and develop new forms of advertising.
Digital Access for only $0.99
For the most comprehensive local coverage, subscribe today.