The Wall Street Journal and other newspapers are reporting federal commodity regulators are looking into allegations that the nation's largest dairy cooperative manipulated prices for milk and cheese. The Dairy Farmers of America controls about one-third of the country's milk supply. Antitrust lawsuits have been filed by farmers and retailers who say the cooperative conspired to suppress prices it paid for raw milk while raising prices to retailers. Both the government and the dairy cooperative are not commenting on the reports. Milk prices remain at almost $4 a gallon.