Announcement of regulated information pursuant to Law 3556/2007
Notification of significant changes in voting rights

In accordance with the Transparency Directive, ELLAKTOR S.A. (hereinafter the “Company” or the “Issuer”) announces the notification received on 18 May 2026 from its shareholders regarding a change in its participation in the share capital and voting rights of the Company, as follows:

The shareholder MOTOR OIL (HELLAS) CORINTH REFINERIES S.A. (“MOH”) notified that, on 15 May 2026 (transaction date), its participation in the Issuer’s share capital and voting rights fell below the thresholds of 20% and 15%, while a change exceeding 3% also occurred.

Following the above, MOH now directly holds 36,250,000 shares and voting rights, corresponding to a 10.41% participation in the share capital and voting rights of ELLAKTOR S.A. (as compared to 78,000,000 shares and voting rights, corresponding to a 22.40% participation prior to the transaction), with no indirect participation.

Additional Information:

The present notification was made as MOH’s participation in the Issuer’s share capital and voting rights fell below the thresholds of 20% and 15%, respectively, while a change exceeding 3% also occurred.

MOH’s previous notification, according to which it held 23.89% of the Issuer’s voting rights, was made on 16.01.2025.

Finally, it is clarified that MOH’s percentage of voting rights in ELLAKTOR S.A., considering the treasury shares held by the Issuer, amounts to 10.47%.

Kifissia, May,18^th , 2026