Twitter Shares Up As Dorsey Named Permanent CEO

Jack Dorsey has said he wants Twitter (Swiss: TWTR.SW - news) "to exceed the world's expectations" for the US tech company as he was confirmed as its chief executive officer for a second stint.

Twitter (Xetra: A1W6XZ - news) 's shares rose as much as 7% after the announcement, which ended months of speculation about who would take the top job at the microblogging service.

Mr Dorsey has been interim CEO to much acclaim since his predecessor, Dick Costolo, stepped down in July.

The company has confirmed to Sky News he will not be paid for the role.

Some investors say the 38-year-old boss is a more effective leader now than in 2008, when he was fired from his first stint as CEO.

Since his interim role earlier this year, he has brought out features including a widely available "buy now" button that allows users to make purchases directly through Twitter.

It (Other OTC: ITGL - news) comes as the company, which he co-founded over nine years ago with Evan Williams, Biz Stone and Noah Glass, tries to expand its audience and end nearly a decade of financial losses.

There are now more than 300 million users of the short messaging service but growth has slowed, frustrating investors, even as people spend more time online, particularly on their smartphones.

Mr Dorsey is also head of the mobile payments company Square and some investors have expressed concerns about whether he could run both companies at the same time.

Square is expected to be floated on the US stock exchange this year and he may have to spend a substantial amount of time trying to woo investors for the IPO.

Mr Dorsey said: "The world needs a Twitter that not only remains relevant, but thrives and continues to redefine what came before it.

"It is our goal to exceed the expectations that the world has for us."

Twitter will now look for a new chairman as Mr Dorsey will not carrying on with that role as well as CEO, but he will continue as chief executive of Square, which he co-founded in 2009.