Ferrous scrap prices have risen as much as $13 a long ton, driven by export demand and the unwillingness of some dealers to sell much scrap this month.

Price moves were anything but uniform. Along the East Coast, the South, in Pittsburgh and Chicago, prices were up an average of between $5 and $10 a ton. In Detroit and Canadian markets, on the other hand, most prices were unchanged.

Offshore demand, particularly along the U.S. East Coast, is still the tail wagging the domestic steel industry's raw material markets far inland. Mills in Ohio and western Pennsylvania as well as on the Eastern Seaboard and in the Southeast have boosted prices for No. 1 heavy melting steel and shredded scrap, industry sources said, an unusual move given the mills' usual practice of not buying much scrap in December in order to...