EU Foreign Minister Josep Borell and Iranian Foreign Minister Mohammad Javar Zarif were scheduled to give an introductory speech at the Europe-Iran business forum scheduled for December 14-16.
More than 3,300 participants were registered for the online conference, which would have focused on economic opportunities in Iran.
Marking against Iran
But following the execution of Iranian journalist and activist Ruhollah Zam, voices have been raised to cancel the conference, including through an online campaign demanding that the EU suspend its participation.
Which has now happened.
On Sunday, the conference organizers published a statement stating that the meeting is postponed to the future.
The statement states no reason why it is being moved - only a hope that the event can take place in the "near future".
Diplomatic sources tell SVT Nyheter that the decision to cancel the conference was made by EU representatives, as a signal against the execution of Ruhollah Zam.
The information seems to be confirmed by the French Ministry of Foreign Affairs, which writes on Twitter that the ambassadors of France, Germany, Italy and Austria to Iran cancel their participation as a result of the "barbaric and unacceptable execution".
Earlier on Sunday, German and French ambassadors were summoned to the Iranian Foreign Ministry to answer for "anti-Iranian" statements that followed the execution on Saturday.
Lived in exile
Ruhollah Zam lived in exile in Paris from where he ran the news site AmadNews.
A site that repeatedly criticized Iranian President Hassan Rouhani and Ayatollah Ali Khamenei.
He was arrested during a trip to Iraq last year and then taken to Iran where he was brought to justice and later sentenced to death, among other things for inciting violence during the regime-critical protests that shook Iran in 2017.