Exchange operator Euronext said trading would resume after it fixed a technical glitch that froze all transactions in Dublin, Amsterdam, Brussels, Lisbon and Paris for more than three hours.
The outage hit trading in cash equities, derivative products and commodity futures across Europe.
"Euronext is preparing for a resumption of all markets but the warrants and certificates one for which investigations continue", the company said.
It said the route cause of the glitch has been identified and resolved, adding that it was a technical issue impacting the middleware system.
Earlier this month Euronext announced it would buy the Milan bourse from the London Stock Exchange group for €4.3 billion.
The outage followed a severe one on the Tokyo Stock Exchange earlier this month, which brought stock markets in Japan to a complete standstill, in the worst ever outage for the world's third largest equity market.
[UPDATE] The route cause has been identified and resolved. It was a technical issue impacting the middleware system. Euronext is preparing for a resumption of all markets but the Warrants and Certificates one for which investigations continue.— Euronext (@euronext) October 19, 2020