Col Allan, editor-in-chief of the New York Post and the longest-serving editor at News Corp., announced on Thursday that he intends to retire at the end of this month after a distinguished career that has included the editorship of two of the world’s leading newspapers.

Commenting on Mr. Allan’s decision, Rupert Murdoch, executive chairman of News Corp., said: “Col Allan is one of the most outstanding editors of his generation. Col’s intelligence, insight, humor and unrelenting energy have created the New York Post that today stands as a newspaper of great influence, in print and online.”

He continued: “He has been a great friend and colleague since he joined in 1974, and I want to thank him on behalf of my family and the company for his service. Col has edited two newspapers for this company, The Daily Telegraph in Sydney, as well as The Post, a very rare achievement in journalism. As editor of The Post, he has driven a news agenda that has been essential reading for New York’s leadership, as well as serving all who live in this great city. Col has sought, without ego or envy, to hold the powerful accountable, to assail corruption and to have a positive impact in New York and beyond.”

During his editorship, the paper has also expanded its digital audience more than tenfold, to a record 31.5 million unique users in March, and expanded its national reach in the US. That success followed his tenure as editor of The Daily Telegraph in Sydney, where he built the paper into one of the most influential and successful in Australia.

Col Allan commented: “It has been an enormous privilege to edit this great paper. Journalists at The Post, from the reporters, to the sub editors, to the photographers to the columnists, are the best in the business, and I know that the paper will continue to grow in scale and influence.”

“Journalism and journalists have a crucial role, particularly in this digital age, and I want to express my deep gratitude to Rupert and the Murdoch family for all they have done to further the cause of journalism around the world. Of course, I am also personally grateful for the extraordinary opportunities they have generously given me over the past four decades.”

Stephen Lynch, currently Sunday editor of the New York Post, has been appointed to succeed Col Allan, beginning on May 1, 2016. Lynch will report to Jesse Angelo, publisher and chief executive of The Post. Mr. Lynch joined The Post in 2003 as a general assignment business writer. He went on to become features editor and then Sunday editor.

Commenting on the announcement, Mr. Angelo said: “Col has been an incredible mentor to me, and a great friend. He is one-of-a-kind, a once-in-a-lifetime colleague, and a great journalist. I speak for the entire staff when I say that he will be dearly missed.

“As for Stephen, he is a brilliant editor, and I am delighted he is taking on this role. He is whip-smart, with a great sense of humor, and a great passion for The Post. I look forward to working closely with him as we take the next step in our storied 215-year history.”