Twitter Boss Resigns As Founder Returns To Helm

Twitter (Xetra: A1W6XZ - news) chief executive Dick Costolo has announced he is stepping down - with the site's co-founder, Jack Dorsey, replacing him.

The social media network has struggled to boost its numbers of users and develop new advertising methods, despite a high-profile public offering on the stock exchange two years ago.

In a statement, Twitter said Mr Dorsey's return would be temporary while a permanent CEO was found.

Sky (Other OTC: BSYBF - news) 's Technology Correspondent, Tom Cheshire, said pressure had been building on Mr Costolo for quite a few months - but the timing of the move was still a surprise.

"Shareholders have been really concerned about the lack of growth. User growth has slowed, especially when you compare it to a behemoth like Facebook (NasdaqGS: FB - news) ," he added.

There has also been shareholder concern that the departing CEO didn't have "the vision" needed to take the tech giant forward.

Shares (Berlin: DI6.BE - news) in Twitter rose by more than 7% in after-hours trading on the New York Stock Exchange following the announcement.

Mr Costolo, who has been with the company for six years, said: "I am tremendously proud of the Twitter team and all that the team has accomplished.

"There is no one better than Jack Dorsey to lead Twitter during this transition. He has a profound understanding of the product and Twitter's mission in the world."

According to the company's statement, Mr Dorsey's first day back in the job will be on 1 July. He was previously Twitter's chief executive between May 2007 and October 2008.