MEXICO CITY (AP) -- Mexico's anti-monopoly regulators on Monday imposed special conditions for a period of 10 years on Walmart's Mexico subsidiary for allegedly pressuring suppliers.

The decision follows a related $4.6 million fine handed down by the regulators, known as the Federal Competition Commission, for alleged monopolistic practices. Walmart de Mexico said last week it plans to appeal the fine.

The company did not immediately comment on Monday's announcement.

The Federal Competition Commission said Walmart must refrain from pressuring suppliers to grant it any discounts offered to competitors, among other things.

"For 13 years, Walmart used its market power to impose abusive conditions on its suppliers, gaining illegal advantages over its competitors," the commission wrote in a statement.

"Walmart had a system that allowed it impose discretional discounts, to force its suppliers not to give better prices or terms to other stores, seriously affecting them, especially those that were small and medium-sized," the statement said.

Walmart de Mexico -- by far the largest retail chain in Mexico -- described the case as unfair and claimed it contained "errors in applying the law."

The anti-monopoly agency, which is soon to be eliminated, levied the fine after at least one rival store chain accused Walmart of using its substantial purchasing power to gain discounts that put other sellers at a disadvantage.

Walmart de Mexico's shares fell about 2.5% on the Mexican stock exchange Monday.