TWITTER chief executive officer Dick Costolo is stepping down, under pressure from investors frustrated by the internet company's slow growth and seemingly constant shake-ups in its upper ranks.
Mr Costolo will be replaced by co-founder Jack Dorsey on an interim basis.
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.
Mr Costolo, who will step down on July 1, will continue to serve on the board, the company said in a regulatory filing.
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