Shares in Trintech shed 6 per cent in Europe after Mr John Maguire, who founded the company with his brother Cyril, stepped down as its president.
Trintech said John, who also resigned from the board of directors, was leaving "to pursue other personal interests".
"He is not going into any competing or auxiliary business. He plans to take a year off and travel," said Mr Cyril Maguire, who replaced John as chief executive of the software group a few months ago.
Cyril, who set up Trintech with his brother in 1987, said John's departure was "very amicable and professional".
Trintech said it had no plans to replace the role of president. The company's chief technology officer, Mr George Burne, along with a number of senior technology personnel, would fill the gap created by John's resignation, according to the company.
Shares in the company fell on the news, closing 6 per cent lower at €1.22 on the German Neuer Markt and were down fractionally at $1.30 on the Nasdaq.
However, analysts in Dublin said John's departure came as no great surprise and resolved a duality that had existed in the company for some time.
"You had two different brothers leading the company in two different directions from two different bases in two continents," one analyst said.
John, who was based in San Mateo in the US, was generally regarded as the technical driver of Trintech.
However, earlier this year he relinquished the role of chief executive to Cyril, who is seen to be more focused on the bottom line given his background in finance and investment.
"The board took a decision around six months ago that what was needed was someone with a more commercial approach to the financial realities," Cyril said.
John had been considering this over the past six months, he said, but there had been "no falling out in that regard".
John's decision not to remain on as a director, despite retaining 15 per cent of the company's shares, reflected a desire to make "a clean break of it", Cyril said. "At the end of the day, he has put 15 years into it," he added.
Analysts believe the changes should be positive for the company in the medium term as it will be able to convey a clearer message to the market.
"You have a single individual now pointing the way and the focus is on getting the company back to profitability," said Mr John Coolican, analyst with Merrion Stockbrokers.
Cyril said yesterday that the market for the secure payment software company remained tough but reiterated that the focus was on moving Trintech back into the black after a number of loss-making quarters.
"We are confident that we can turn that corner by the end of the year," he said.