Continental AG's North American unit is recalling about 391,000 tires, most of which were put on new Ford Motor Co F-250 and F-350 heavy duty pickup trucks, U.S. regulators said on Friday.

About 330,000 were put on the new trucks, and some were sold as replacements, Continental said of the tires made in Mexico from May 2007 to September 2008.

Ford spokesman Wes Sherwood said the tire recall affected 65,000 pickup trucks in the United States and Canada.

Vehicles affected are trucks for model years 2008 and 2009. Each truck typically has four tires and a spare. Ford will be providing Continental with its owner information.

Continental will replace the tires, some of which may experience uneven wear and vibration, the company said in a letter to the U.S. National Highway Traffic Safety Administration. The main concern is that when the trucks are overloaded or the tires are under-inflated, separation between the belt edges potentially leading to a tread detachment can occur.

(Reporting by Bernie Woodall, editing by Gerald E. McCormick and Lisa Von Ahn)