Dear Shareholders,

PetroVietnam Technical Services Corporation respectfully sends to Valued Shareholders and interested Investors Official Letter No. 1542/PTSC-BTK dated September 24, 2026 regarding Disclosure of information on the Resolution and Decision of PTSC’s Board of Directors regarding the Restructuring of PTSC’s Branches, including the following documents.

1. Resolution No. 675/NQ-PTSC-HDQT dated September 23, 2026 issued by the Board of Directors of PetroVietnam Technical Services Corporation regarding the Approval of the restructuring plan for the Branch of PetroVietnam Technical Services Corporation - PTSC Marine.

2. Decision No. 676/QD-PTSC-HDQT dated September 23, 2026 issued by the Board of Directors of PetroVietnam Technical Services Corporation regarding the Termination of operations of PTSC Geos and Subsea Services - Branch of PetroVietnam Technical Services Corporation.

, as detailed in the attached document.

Sincerely./.

Attachment:
1542/PTSC-BTK