In a statement Trinity Mirror said that Sinyor had resigned as a director of the company and had left by mutual consent. It said that the position of chief executive newspapers was now redundant following the appointment of Bailey, who is due to take up her new role on February 3.
Outgoing Trinity Mirror chief executive Philip Graf, said: "I thank Joe very much for his considerable contribution over the past two years during which time the company has made significant progress in a tough market. We wish him every success for the future."
Sinyor is thought to have been one of the internal candidates in the race to takeover from Graf. Reports suggested that his departure was linked to a disagreement with Trinity Mirror chairman Sir Victor Blank. The disagreement was thought to centre on strategy and a possible sell-off of the group's national newspapers, which is opposed by Sir Victor.
Last year Sir Victor clashed with US investment bank and Trinity Mirror shareholder Tweedy Browne, after it called for the sale of the national newspapers, including the Daily Mirror.
Sinyor is the former managing director of Sony UK who joined Trinity Mirror in 2000 following the departure of Roger Eastoe.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .