Trading resumed at 0910 GMT after the brief suspension.
Monday marked the start of trading of European carbon futures and options on ICE's Netherlands-based exchange in Amsterdam, after a migration from London, as a result of Britain's departure from the European Union.
EU carbon allowances (EUAs) are the currency used in the EU's emissions trading system (ETS), the 27-member bloc's main tool to help reduce greenhouse gas emissions that cause climate change.
Trading in the EUA benchmark Dec-21 contract resumed at 49.34 euros per tonne and traded 51.47 euros/tonne at 1243 GMT.
EUA futures trades that were conducted prior to the market re-opening were cancelled by ICE Endex, the exchange said in a statement.
Trading of British emission allowances, which started last month, is being operated from London and was not affected by the issue, the spokeswoman said.
European emission allowances could be traded on rival exchange European Energy Exchange, based in Germany, throughout the suspension on ICE Endex. On the EEX, the Dec-21 EUA traded at 51.47 euros/tonne.
(Reporting by Nora Buli; Editing by Kirsten Donovan, Edmund Blair and David Evans)
By Nora Buli
