The chief executive of Twitter has quit the social network.

Dick Costolo announced that he had decided to leave the California-based company at the beginning of July.

In a statement, he said: “I am tremendously proud of the Twitter team and all that the team has accomplished together during my six years with the company.

“We have great leaders who work well together and a clear strategy that informs our objectives and priorities.”

He added: “I am deeply appreciative of the confidence the board, the management team and the employees have placed in me over the years, and I look forward to supporting Twitter however I can going forward.”