MADRID, May 7 (Reuters) - Spanish builder OHL said on Thursday it has launched an internal investigation into accusations of illegal behaviour by its Mexican unit and reiterated that it had not acted illegally in the country.
Shares of OHL's unit tumbled to a four-month low in Mexico on Wednesday after the release of recordings that appeared to show executives discussing overcharging the government but which the company dismissed as a montage.
"OHL Mexico has said that business development is strictly in line with the law, within the contracts it has signed and the best corporate practices. It expressly denies the existence of any kind of irregular activity in its relations with the State of Mexico," the Spanish company said in a statement.
Shares in OHL were down 7.2 percent at 0730 GMT on the Madrid stock exchange, to 18.72 euros per share. (Reporting by Paul Day; Editing by Julien Toyer)