Aldi said what they were doing inflated the cost of the pork it bought ever since 2009.
It is asking the court in Illinois to conduct a jury trial and, if it wins, to be awarded triple damages.
ldi's lawsuit comes several weeks after retailers including Albertsons, Kroger and Hy-Vee filed a price-fixing case against large pork processors, and late last year, a number of large restaurant chains also filed suit.