In a statement published Thursday on the Web site of the Basque-language newspaper Gara, the group said: "A new political time is emerging in the Basque Country. We have a historic opportunity to find a just a democratic solution for the centuries' old political conflict."
ETA formally announced a "definitive cessation of its armed activity," CNN reported. The announcement follows international efforts to push the group to end its nearly 50-year campaign of violence, bombings and shootings.
In a televised address in Madrid, Spanish Prime Minister Jose Luis Zapatero hailed what he called the end of ETA, The New York Times reported.
The group said it was influenced by a one-day conference in San Sebastian Monday in which Sinn Fein nationalist leader Gerry Adams of Northern Ireland and former U.N. Secretary-General Kofi Annan appealed for peace. The meeting did not include representatives of the Spanish government or the Basque regional government, CNN said.
ETA, listed as a terrorist organization by Spain, France, the European Union and the United States, has demanded a separate Basque state in northern Spain and southwestern France.
Leaders at the San Sebastian conference called on Spain and France to agree to direct talks with ETA.