Cemex, the world’s No. 3 cement maker (CMXCPO.MX) (CX.N), said in the filing with the U.S. Securities and Exchange Commission that the search was part of an investigation of building materials companies in Spain “for possible unlawful practices consisting of price fixing and market sharing agreements.”

The filing said that if any companies were found guilty, they could face a penalty of up to 10 percent of total sales volumes. – Spain’s Government must be salivating at the prospects of getting some money for its cash strapped country.

Last year, the European Commission started a probe into possible cartel activity in the cement sector. Cemex said it had not been able to confirm whether the Spanish investigation was in addition to the EU probe.

* Lawsuit latest concern for debt-laden Mexican company

* Cemex says sand, gravel not subject to royalties (Recasts; adds background, Cemex debt details)

By Robin Emmott

MONTERREY, Mexico, June 23 (Reuters) – The U.S. state of Texas said on Tuesday it filed a lawsuit against Mexico’s Cemex SA for $558 million in royalties owed in the United States, the latest headache for the debt-laden cement maker.

Texas Land Commissioner Jerry Patterson said Cemex (CMXCPO.MX)(CX.N), the top cement maker in the United States, was mining a quarry near El Paso, Texas, without paying royalties to the owner, the state’s Permanent School Fund.