BRUSSELS - European Union governments have reached a preliminary agreement to ban imports of Iranian crude to the EU but have yet to decide when such an embargo would be put in place, EU diplomats said on Wednesday.The agreement, news of which sent crude oil prices higher, followed talks in the last days of December between EU envoys, diplomats said. Objections to the idea, notably from Greece, were dropped during the talks, they said."A lot of progress has been made," one EU diplomat said, speaking on condition of anonymity. "The principle of an oil embargo is agreed. It is not being debated anymore."A European ban on Iranian crude would be part of concerted Western action to put pressure on Tehran to abandon its nuclear program, which many governments worry aims at producing an atom bomb. Tehran says its aims are peaceful only.