OBRASCÓN HUARTE LAIN, S.A. (“OHLA” or the “Company”), pursuant to article 227 of Law 6/2023, of 17 March, on the Securities Markets and the Investment Services, hereby notifies the Spanish National Securities Market Commission (Comisión Nacional del Mercado de Valores) (“CNMV”) the following

OTHER RELEVANT INFORMATION

Following the communications of other relevant information published by the Company on 7 and 23 September 2026 (with official registry numbers 42,614 and 42,854) in connection with the consent solicitation process related to the Company’s subsidiary OHL Operaciones, S.A.U. (the “Issuer”) Split Coupon Senior Secured Notes due 2029 (ISIN: XS2356570239 / XS2356571120) (the “Notes”) for the approval of resolutions (the “Noteholder Resolutions”) set out in the consent solicitation memorandum published by the Issuer on 7 September 2026 (the “Consent Solicitation Memorandum”), the Company announces that the Consent Solicitation process ended at 11.00

a.m. (CET) on 24 September 2026 and has obtained the approval from holders (the “Noteholders”) representing more than 75 per cent. in aggregate principal amount outstanding of the Notes.

Accordingly, the Noteholder Resolutions are binding on all Noteholders and the noteholders’ meeting, of which notice was given pursuant to the Consent Solicitation Memorandum, will not be required to be held.

Capitalised terms used in this announcement have the same meaning ascribed to them in the Consent Solicitation Memorandum.

Madrid 25 September 2026.