Lars-Christer Olsson has stepped down from his position as Uefa's chief executive officer.
The Swede was a close ally of fellow countryman Lennart Johansson who lost out to Michel Platini in the battle for Uefa's presidency last week.
Platini made no secret of his intention to take a far greater role as executive president of the organisation and Olsson said that a difference of opinion prompted his decision to move on.
"I would have liked to stay on, but there was a difference of views on how we go forward under the new administration," he said.
"Michel Platini is a good person as an individual. This is all part of the game. Once the new regime took over, I felt it was time to go," Olsson added.
Olsson succeeded Gerhard Aigner in 2004 and Platini has paid tribute to the Swede.
The Frenchman said: "Over the past three years he has worked hard to continue the dialogue between Uefa and all of European football's stakeholders and together they have achieved a great deal in a very short period, most notably the continued re-distribution of income from the European Football Championship and the UEFA Champions League, closer links with all our member associations, and the introduction of thousands of mini-pitches across Europe.
"I am sure these initiatives will serve as a solid base for further development and will provide a lasting legacy for the European football family as a whole.
"On behalf of the European football family I therefore take this opportunity to thank Lars-Christer for his dedication and hard work to the game of football, both with the Swedish FA and at Uefa, and to wish him all the very best for the future."
Italian Gianni Infantino has been appointed as the interim chief executive officer of Uefa.