LONDON, March 21 An attack on Iran would push oil prices beyond $100 per barrel, a former Saudi Arabian oil minister said in London."If America or Israel attacks Iran ... the prices of oil will go three digits," former Saudi Oil Minister Sheikh Zaki Yamani said. Oil was around $60.15 Wednesday. Yamani said high oil prices bolster supplier countries, but said the Organization of Petroleum Exporting Countries, prefer prices between $50 and $60 per barrel, the global energy information firm Platts reports.Yamani said OPEC could curb its production quota cuts if non-OPEC producers reduced production. OPEC cuts were intended to halt oil price drops following record highs last summer.High oil prices provide incentives to reduce consumption and move to alternative sources of energy, whereas too low oil prices reduce the profit returns for companies.An attack on Iran could shut that country's market, which produces about 4 billion barrels per day, as well as have reverberating effects through the Middle East region.The military option is still possible in the ongoing row between the United States and other countries who believe Iran's nuclear program is for weapons purposes.Copyright 2007 by UPI