The culture ministers of the three countries wrote in a letter to the European Commission urging concerted measures against the illicit trade in cultural treasures for the benefit of the jihadist group.
"By taking part directly or indirectly in the trade in cultural artifacts from archaeological digs, museums and libraries finance their (Isis's) atrocities in the region and in Europe," Monika Gruetters, Dario Franceschini and Fleur Pellerin wrote.
They said they had agreed at a meeting of EU culture ministers on November 24th, in the wake of last month's deadly Isis assault in Paris, that it was "high time for Europe... to take more effective action against these attacks on our cultural heritage and the trade in cultural assets".
Among steps the ministers called for were uniform EU import and export rules, more reliable certification of traded antiquities and expedited means to return plundered goods to their countries of origin.
In territory it controls in Iraq and Syria, Isis finances itself through means including oil smuggling, extortion, kidnapping for ransom and selling looted antiquities.
The United States and Russia said last week that they were drafting UN resolutions aimed at ramping up global efforts to choke off Isis's sources of financing.
The proposed new Security Council measures would build on a resolution adopted in February that sought to cut off millions of dollars in earnings from IS smuggling of oil and antiquities.
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