General Updates

Hindustan Oil Exploration Company Limited ‘Lakshmi Chambers’, 192, St. Mary’s Road, Alwarpet, Chennai - 600 018. INDIA. Phone: 91 (044) 66229000 ● Fax: 91 (044) 66229011 / 66229012 E-mail: contact@hoec.com ● Website: www.hoec.com CIN: L11100GJ1996PLC029880 September 01, 2026 By Online The Listing Department The Corporate Relationship Department National Stock Exchange of India Ltd., BSE Limited “Exchange Plaza”, Bandra Kurla Complex, 1st Floor, P. Jeejeebhoy Towers, Bandra (East), Mumbai – 400 051 Dalal Street, Mumbai – 400 001 Stock Code: HINDOILEXP Stock Code: 500186 Dear Sir / Madam, Sub: Disclosure as per Regulation 30 of SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015 (“SEBI Listing Regulations”) HOEC is pleased to inform you that the Government of India has approved the award of Contract Area MB/OSDSF/MUMBAI OFFSHORE/2025 under the Discovered Small Field (DSF) Bid Round-IV to Hindustan Oil Exploration Company Limited (HOEC). The award has been communicated by the Directorate General of Hydrocarbons (DGH), Ministry of Petroleum & Natural Gas, Government of India, vide its letter dated 31 August 2026. The award is subject to execution of the Revenue Sharing Contract (RSC) between the President of India and HOEC. As communicated by DGH, the bid work programme, commercial terms, area, map and coordinates forming part of HOEC’s bid will be incorporated in the final RSC. The date and modalities for execution of the RSC will be communicated separately. The awarded Contract Area is located in the Mumbai Offshore basin and comprises multiple discovered field areas - C-23-9, C-39-14, BH-68, WO-5-11 and B-174-1, together with their respective geographical boundaries and existing well locations. The award further strengthens HOEC’s presence in the Western Offshore, where the Company already has an established operating presence in B80 field and are planning the development of B15 field which was awarded to it in 2025 by the Government of India. HOEC intends to evaluate the discovered hydrocarbons within the awarded area with a focus on accelerated and capital-efficient development, including opportunities for integration, infrastructure sharing and operating synergies with its existing and emerging Western Offshore portfolio. Yours Sincerely, For Hindustan Oil Exploration Company Limited G. Josephin Daisy Company Secretary & Compliance Officer Registered Office: ‘HOEC HOUSE’, Tandalja Road, Off Old Padra Road, Vadodara - 390 020. INDIA. Phone: 91 (0265) 2330766 ● E-mail: contact@hoec.com ● Website: www.hoec.com