Dick Costolo is stepping down as chief executive of Twitter, the company has announced.
The
social messaging service's co-founder Jack Dorsey will take over as
interim chief on 1 July and stay until a replacement can be found.
Mr Costolo had been under pressure from investors unhappy with
the firm's user growth.
In a statement, he said he was "tremendously proud of the Twitter team".
Twitter said that its board had formed a committee to undertake the task of finding a successor.
Following the announcement, shares in the company jumped by more than 7% in trading after US markets had closed.
In announcing his resignation, Mr Costolo said in a statement:
"I am tremendously proud of the Twitter team and all that the team has
accomplished together during my six years with the company.
