Primedia Inc. has placed the assets of its supplementary education group up for sale. Among the properties to be sold are Weekly Reader, American Guidance Service, Films for the Humanities and Sciences and Primedia Reference, which includes such units as World Almanac, Facts on File, Funk &Wagnalls and Gareth Stevens. Not included in the sale are Channel One and Workplace Learning.

Primedia's education group had total sales of $330 million in 1998; the assets put on the block accounted for approximately one-third of the group's sales, or $110 million. Companies likely to be interested in the Primedia properties include Tribune Co., Scholastic and Torstar.

Primedia reported that it is selling the group to better target its operations on the consumer and business-to-business markets. The company will use the proceeds from the sale to pay down debt.