New York, June 12 (IANS): Twitter's chief executive officer (CEO) Dick Costolo has decided to step down in July, the company's top brass announced.

Twitter co-founder Jack Dorsey, chairman of the board and first CEO, will fill the gap as interim CEO when Costolo relinquishes the top post on July 1.

Costolo, who will remain on Twitter's board of directors, repeatedly characterised the departure as his call, in a briefing with shareholders on June 11.

"I initiated conversation with some members of the board at the end of last year about CEO succession as I contemplated what was next for me," Costolo was quoted as saying.

"And ultimately following discussions with the full board at the last week's meeting, we agree that now is the right time to begin this transition."

Twitter has been in the middle of major controversies recently, such as widespread piracy of the Mayweather v Pacquiao title fight using the company's new streaming video platform, Periscope.

Then there are lingering issues related to trolling and bullying on the micro-blogging site, which critics say Twitter has not addressed very efficiently.

Within five minutes after the news came out, Twitter's stock spiked in after-hours trading from $35.75 to $39.29.