Mullins' responsibilites are expected to be absorbed by Paul Hayes, the managing director of Times Newspapers, and his senior team.
Following a lengthy search for a managing director, Mullins is expected to join the Standard in the new year.
The Standard, which is suffering from a declining circulation following the launch of the free publications thelondonpaper and London Lite, has been on the hunt for a managing director since Mike Anderson departed to join News Group more than a year ago. Bert Hardy was drafted in to fill the role in a caretaking capacity, but he has been suffering with ill health.
Mullins, who has worked at News International for six years and is a former marketer at Unilever and Diageo, faces the challenge of turning the fortunes of the Standard around. Last month, the paper suffered a 14 per cent drop in its circulation to 281,915.
Sources at Associated also suggested that the role is likely to be a demanding one, due to the importance of forging a strong relationship with the Standard's editor, Veronica Wadley, and her boss, the Daily Mail editor and Associated editor-in-chief, Paul Dacre.
Mullins said: "I am looking forward to working with the editorial and commercial teams at the Standard. I am sure it will be immensely rewarding and a lot of fun."