MONTERREY -- Mexican companies must pay tax in Mexico on investments in countries where there are no taxes or where levies are 75% lower than in Mexico, the country's Supreme Court ruled September 8th, overturning a ruling that protected the world's third-largest cement maker, Cemex, based in Monterrey.

Cemex won an earlier ruling by a lower court to reduce its taxes owed from investments in overseas tax havens. The Supreme Court did not determine how much Cemex will owe or indicate where the investments are. Cemex operates in 50 countries.

The ruling comes as Cemex faces a sharp slow down in its top market, the United States, due to the downturn in the construction market.

Cemex has said that the company will respect the court's decision.