Aer Lingus chief executive Christoph Mueller (pictured) has been appointed as the new chairman of An Post.
The German national's appointment comes as the semi-state firm faces a "critical time" in determining its future, said Communications Minister Pat Rabbitte.
An Post has a "great brand" and an important nationwide network but is facing significant challenges, the minister said.
Falling profits mean the company will raise the price of a basic stamp from next week.
Mr Mueller takes over at An Post from John Fitzgerald, the former Dublin City manager who had been appointed to the chairman role in 2008. He was paid €31,000 for the part-time position in 2011.
"The company will benefit from the strategic leadership approach that Christoph Mueller has brought to Aer Lingus. I am also sure that Christoph, who played a leadership role in Deutsche Post and DHL before joining Aer Lingus, will bring a valuable international perspective to the Board of An Post," said Mr Rabbitte.
Mr Mueller was the chief financial officer of DHL Worldwide between 2002 and 2004.
In 2004 he was appointed a member of the executive committee of Deutsche Post after the company acquired DHL.
He subsequently worked with travel group TUI and was appointed chief executive officer of Aer Lingus in 2009.
An Post employs 9,000 people and has been attempting to cut costs and boost revenue as it faces increased competition.
It told the postal regulator Comreg last year that it wants to axe the equivalent of 1,500 full-time jobs by 2016. That would bring its total job cuts to 2,600 since 2008.
News of his appointment came as representatives of the Irish Postmaster's Union (IPU) said the national post office network could be vulnerable if contracts for handling social- welfare payments and savings bonds are lost.
The union said it welcomed a report by the Joint Oireachtas Committee on Transport and Communications that backs using the Post Office to provide government services.
The IPO represents 1,000 postmasters and postmistresses who run post offices but are not employed by An Post.
The contract for handling social-welfare payments has been put out to tender.
The German executive is well regarded in aviation circles for having transformed the financial fortunes of Aer Lingus since his appointment.
He has slashed costs, returned it to profitability and fought off takeover approaches from Ryanair.
At An Post Mueller will preside over a massive board of directors – with 19 members who between them were paid a total of €244,000 in 2011, down from €251,000 in 2010.
That excludes the chief executive, Donal Connell. In 2011, he was paid a total of €495,000. He has waived 15pc of his basic €381,000 salary. He was appointed to the role in 2006.
An Post's operating profit slumped from €5.8m in 2010 to €2.2m in 2011 even as revenue remained largely unchanged at €806.7m.