Significant Event. Announcement of 1Q2018 Results presentation and Capital Markets Day 2018

OBRASCÓN HUARTE LAIN, S.A. (“OHL” or the “Company”), pursuant to article 228 of the consolidated text of the Spanish Securities Market Act approved by Royal Legislative Decree 4/2015, of 23 October, hereby notifies the Spanish National Securities Market Commission (Comisión Nacional del Mercado de Valores) (“CNMV”) the following SIGNIFICANT EVENT

OHL will release 1Q2018 Results on Tuesday May 15th after market closing.

On the next day, Wednesday May 16th at 11:00am CET/10:00am GMT, the President of OHL Group Mr. Juan Villar-Mir will hold a Capital Markets Day in Madrid for analysts and investors to explain the main goals and fundamental lines of work of the Company for 2020 horizon.

The presentation can be followed live via webcast in Spanish and English through www.ohl.es. The backup documentation for this presentation will be made public on May 16th before market opening through its filing with the CNMV and its publishing at the corporate website.

The recording will be available at the website for a week time.

Madrid, May 7th 2018