Dorsey will lead product development as the micro-blogging site looks to boost revenues and compete with Facebook’s for a greater share of the online ad market.
It was announced by Twitter CEO Dick Costolo on Twitter yesterday (28 March).
Dorsey followed on Twitter saying: “Today I’m thrilled to get back to work at @Twitter leading product as Executive Chairman. And yes: leading @Square forevermore as CEO. #200%”
In an official statement Twitter said: “As executive chairman, Jack will dive in to work with more than 450 people, led by an experienced executive team.”
“The timing is fortuitous; not only is Twitter experiencing record growth, but we also now have a new infrastructure that will keep us ahead of that growth and enable us to launch products that will make Twitter more instant, simple and always present.”
Dorsey will also continue to lead his mobile payment start-up Square.
Twitter celebrated its fifth birthday last week, read a history of its development here.