Twitter’s board members have rejected choosing co-founder Jack Dorsey as permanent CEO while he shares a CEO role with Square, a social media company he also co-founded.

"The Committee will only consider candidates for recommendation to the full Board who are in a position to make a full-time commitment to Twitter," Twitter’s Board of Directors said in a statement.

Dorsey will be appointed as interim CEO of the company following Dick Costolo’s resignation due to take effect on July 1.

Dorsey created the concept behind the social media platform, and was the company’s first CEO until he was dismissed in 2008.

The firm’s board said it will consider both internal and external candidates to take charge, including Adam Bain, Twitter’s president of revenue and partnerships, and Anthony Noto, Twitter’s CFO.

Peter Currie, Twitter’s Lead Independent Director and Chair of the Search Committee, said: "We are confident in Twitter’s product roadmap and excited by the current pipeline. We also believe much more can be done to realise Twitter’s enormous unmet long-term potential.

"In our next CEO, we are looking for a bold thinker and proven leader capable of helping Twitter fully capitalise on its unique platform for the benefit of users, advertisers and employees, and to maximise value for investors in the years ahead."