The latest chapter in the ongoing speculation and saga of who will run Twitter has come to an end.
The microblogging service will be headed by co-founder Jack Dorsey, according to a filing with the US Securities and Exchange Commission, posted Monday.
Dorsey will relinquish his title as Twitter board chairman, but will remain chief executive of payments service Square.
On a conference call with media and analysts, Twitter board member Peter Currie said the next chairman would be an outside recruit. No name is being revealed at this time as Currie said the search is ongoing.
It was also just announced that former Twitter CEO Dick Costolo would step down from the board effective immediately.
Adam Bain has been appointed chief operating officer and will assume more leadership responsibilities throughout Twitter in order to support Dorsey as he officially takes on dual CEO roles.
Dorsey said in a series of tweets following the announcement that the company is "working hard" on strengthening the team.
Referring to Square, he added: "Both companies have strong businesses and are well positioned to grow their impact in the world. I will do whatever it takes to ensure that."
Speaking to the board's decision process in naming Dorsey as Twitter's permanent CEO, Currie said it became clear over the past few months that Dorsey "was not only meeting but surpassing expectations" of the board's CEO criteria.
Twitter's stock was up more than 6 percent in pre-market trading in response to the news.
Following months of speculation and murmurs by media, investors and analysts alike, Dick Costolo stepped down as Twitter's CEO in June -- although he would remain on the company board, until today.
In a bigger twist, the San Francisco-headquartered company added Dorsey would be stepping up as interim CEO, effective July 1.
Also CEO and co-founder of digital payments company Square just down the street, Dorsey is no stranger to the top perch at Twitter.
Dorsey served as Twitter CEO for two years before co-founder Evan Williams replaced him in 2008.
Dorsey remained at Twitter on the board, eventually rising to executive chairman.
Costolo first joined Twitter in 2009 as the micro-blogging giant's new chief operating officer. The Google veteran was soon promoted to CEO in 2010 as Williams was also pushed out.
Also a comedian before he pivoted toward a career in tech, Costolo has often been credited for establishing Twitter's first revenue streams after years in the red and sole reliance on venture capital money.
Problems possibly reached a breaking point amid the last earnings announcement in April in which the first quarter report released early before the markets closed, apparently sourced from the company's investor relations website.
Costolo told shareholders in June that the decision to bring on Dorsey as interim CEO was part of the decision to make the new CEO search as open and public as possible. He added Twitter wants to "avoid speculation and rumors if we tried to attempt a CEO search privately."
"There is never, ever, a perfect time for a transition like this," Costolo admitted at the time.
Natalie Gagliordi and Zack Whittaker contributed to this report.