Twitter appears to have hinted that its co-founder Jack Dorsey will not become the permanent CEO once Dick Costolo leaves, Digital Spy reports.

Dorsey will take over as interim CEO from July, following Costolo's resignation earlier this month - but Dorsey will also keep his job as Square chief executive at the same time.

In a statement regarding Twitter's CEO recruitment process, it is made clear that they want someone able to make "a full-time commitment" to the microblogging site.

The Board has assembled a search committee, which includes leading global executive search firm Spencer Stuart, to identify potential candidates.

"The Board has the utmost confidence in the strong management team Dick has assembled and in Jack Dorsey's ability to lead the company on an interim basis while we identify a permanent CEO," Twitter's lead independent director and chair of the search committee Peter Currie said.

Dorsey may not be the temporary boss for too long either, as the statement says that "the search is proceeding with a sense of urgency".

Costolo steps down from Twitter after five years at the top, but will remain on its board of directors.