Significant Event. Consideration about the potential integration of the construction business of Caabsa and OHL

OBRASCÓN HUARTE LAIN, S.A. (“OHL” or the “Company”) in compliance with the provisions of article 226 of the Refunded Text of the Securities Market Act approved by Royal Decree Law 4/2015 of 23rd October informs the National Stock Market Commission (“CNMW” for its Spanish initials) of the following:

PRIVILEGED INFORMATION

The Company puts in knowledge of the market that today it has received a letter from Mr Luis Fernando Martín Amodio Herrera and Mr Julio Mauricio Martín Amodio Herrera to consider the potential integration of the construction business of Caabsa Infraestructuras, S.A. de C.V.(entity owned by the Amodio family) (“Caabsa”) and OHL through a potential merger by absorption of the above mentioned construction business into OHL that would grant the Amodio family a stake of no less than 31% and no more than 35% of the share capital of the Company.

In any case, a potential merger between OHL and the construction business of Caabsa, if applicable, would be subject to the authorization of the CNMV regarding Caabsa exemption from its obligation to prepare a public takeover bid on OHL shares as this merger has an industrial or business purpose according to the provisions of article 8.g) of Royal Decree 1066/2007 of 27th July on the regime of public takeover bids on the acquisition of shares.

The Company has convened the Board today at 10.00 am to discuss the letter received from the Amodio family.