Former Guardian readers' editor Chris Elliott has joined alternative press regulator Impress as a consultant.
The former managing editor stepped down from his complaints-handling role last month.
The paper advertised for a new global readers' editor six months ago but has yet to announce a replacement for Elliott.
Impress chief executive Jonathan Heawood said: "We are delighted to welcome Chris and we are thrilled to have such an experienced journalist join the team.
"Chris is a heavyweight when it comes to ethics, media standards and press freedoms. He has been at the forefront of high profile issues at the Guardian, where, as the former readers' editor and managing editor, he championed for more effective and efficient working practices for both print and digital editions and negotiated a new freelance charter leading to consistent fees, rights and intellectual property terms."
Elliott said: "I am delighted to be helping Impress establish simple, honest and transparent systems for dealings with readers' complaints at each of their new clients.
"A willingness to face up to the fact that journalists get things wrong and deal with it is crucial in a digital age where each news organisation needs to build trust with readers if it is to survive and thrive.
"That belief is at the core of the values of Impress. I am very happy to be part of that."
Elliott worked for 12 years on regional newspapers before joining the Sunday Telegraph as a reporter.
He had stints at the Sunday Correspondent and The Times before moving to the Guardian in 1995 as a reporter and news editor.
He was appointed managing editor in 2000, became joint managing editor of the Observer and Guardian in 2008.
In 2010 he became the Guardian readers' editor, stepping down from the post at the end of last month.
He was also a member of the Guardian News and Media (GNM) board for three years.
In addition to his consultancy work with Impress, Elliott would be advising the Ethical Journalism Network and working with Concern UK, a development charity, Impress said.
Impress has applied to the Press Recognition Panel for recognition under the Royal Charter as a press regulator. At present it has fewer than 20 members signed up, none of which are major newspaper or magazine publishers.
The Guardian, Evening Standard, i and Financial Times are the only UK national newspapers not signed up to the main press regulator IPSO. They all currently regulate themselves.