WASHINGTON (REUTERS) - Twitter Inc named interim Chief Executive Jack Dorsey as its permanent CEO on Monday.

Mr Dorsey has served as interim CEO for the past three months, after former Dick Costolo stepped down on July 1.

Mr Dorsey will remain the head of fast-growing mobile payments company Square, potentially setting up a conflict of interests for the co-founder of both companies.

Twitter previously said the CEO job would be a full-time position, which seemed to exclude Mr Dorsey as long as he continued to run Square.