Business & Economy

Dick Costolo will step down as Twitter CEO on July 1

Dick Costolo of Twitter attends TechCruch Disrupt SF 2013 at San Francisco Design Center on September 9, 2013 in San Francisco, California.
Dick Costolo of Twitter attends TechCruch Disrupt SF 2013 at San Francisco Design Center on September 9, 2013 in San Francisco, California.
Steve Jennings/Getty Images for TechCrunch

Dick Costolo will step down as CEO of Twitter after almost five years. He did not disclose a reason for his departure.

Twitter Inc. announced the move in a press release Thursday and Costolo also tweeted the news through his own account.

The San Francisco company says co-founder and Chairman Jack Dorsey, 38, will be its interim CEO while it looks for a replacement.

Costolo, 51, will stay on Twitter's board of directors. He has been a director since September 2009 and became CEO in October 2010.