A statement from publisher Northcliffe Media said he was leaving “to pursue other interests.”
The move comes just 48 hours after the WMN turned in what is being seen as the best sales performance of any English regional daily in the most recent ABC figures, achieving a decrease of just 1pc without the need for bulk giveaways.
Alan, who has been the paper’s editor since 2005, becomes the seventh Northcliffe daily editor or weekly group editor to leave the business in the past year. His last day will be 11 April.
His decision follows those of Jon Grubb (Lincolnshire Echo), John Meehan (Hull Daily Mail), Keith Perch (Leicester Mercury), Marc Astley (Express & Echo), Malcolm Pheby (NottinghamPost) and Andy Cooper (Cornwall and Devon Media).
Alan first joined the company in 2001 as editor of the Plymouth Evening Herald, having previously worked as news editor at the Daily Express. He began his career at the Liverpool Daily Post and Echo.
Said Alan: “I have been immensely proud to work for Northcliffe Media and make a real difference to some of the communities I served.
“It has been a privilege to work with such a professional and talented editorial team who helped me transform the Western Morning News into one of the best performing titles in Northcliffe.
“The Western Morning News has been deeply rooted in Westcountry communities and traditions and has campaigned hard for them and long may this continue.”
Last year the Morning News became the first newspaper to be directly awarded a £1m grant from the Regional Growth Fund to create jobs in areas affected by public spending cuts.
Andrew Blair, managing director of Northcliffe’s South West Media Group, said: “Alan leaves the Western Morning News in a very healthy state, with one of the best circulation performances in the industry.
“We are grateful for his contribution to the business and wish him well in his future endeavours.”