FINDLAY, Ohio (Dec. 7)—Cooper Tire & Rubber Co. has reorganized its tire division into three divisions and named presidents to oversee all manufacturing, sales and distriubtion for each. Mark F. Armstrong will lead the North American Tire Division, with responsibility for passenger and light truck tires on the continent. As president of the International Tire Division, D. Richard Stephens will not only watch over all operations for tires outside of North America, but also take responsibility for business development for all of Cooper Tire. From a new Findlay base, Larry J. Enders will head up the Commercial Products Division encompassing radial medium truck tires, tubes and retread products. In a related move, Cooper named William S. Klein executive vice president of Cooper Tire. He will oveersee engineering, quality assurance and the operations planning committee.