United States Twitter

Dick Costolo: Mr Costolo will be replaced by co-founder Jack Dorsey on an interim basis, according to Australian Broadcasting Corporation. In a statement, Mr Costolo said he was "tremendously proud" of his six years at Twitter. "I am deeply appreciative of the confidence the board, the management team and the employees have placed in me over the years," he said. Related Story: Twitter becomes victim of social media as profit results released early Map: United States Twitter chief executive officer Dick Costolo is stepping down, under pressure from investors frustrated by the internet company slow growth and seemingly constant shake-ups in its upper ranks. Mr Costolo, who will step down on July 1, will continue to serve on the board, the company said in a regulatory filing. After the news, the company shares rose 7.7 per cent to $38.60 in after-market trading. "Unfortunately this news isn't surprising," said Nate Elliott of management consultant Forrester Research. "The bottom line is that Twitter isn't very good right now at serving either its users or its marketers." External Link: Twitter responds #thankyou Dick Twitter was abuzz on Thursday afternoon with tweets reacting to the news of Mr Costolo departure. External Link: Twitter tweets about its CEO changeover He has agreed to cancel all of his remaining unvested equity in Twitter after July 1. (news.financializer.com). As reported in the news.