French Defense Minister Herve Morin, at a meeting of EU defense ministers in Deauville, France, said the operation would begin in November, the BBC reported Thursday.
"There is very broad European willingness. Many countries want to take part," Morin said.
The decision follows pirates' seizure of a ship carrying 33 tanks and demanding a $20 million ransom for its release. The International Maritime Bureau reported three more attempts to seize ships off the African country's coast overnight Wednesday.
"There are continuing attacks in the Gulf of Aden and off Somalia," said IMB's Capt. Pottengal Mukundan. "It is a matter of great concern. We need more resources to deal with the problem."
Kenyan police arrested a maritime official who said tanks on the Ukrainian ship were headed for southern Sudan instead of Kenya, the British broadcaster said.
Andrew Mwangura, spokesman for the Kenyan chapter of the Seafarers Assistance Program, could be charged with issuing an inflammatory statement, officials said.
The Faina, carrying T-72 tanks, rifles and heavy weapons when it was seized last week, is being held off the Somali coast near the town of Hobyo. The ship is surrounded by U.S. warships, the BBC said, and a Russian frigate was approaching the area to join the blockade.