The Earnings Call Invite with respect to the unaudited financial results of the Company for the quarter ended June 30, 2026 is enclosed.

Hindustan Oil Exploration Company Limited ‘Lakshmi Chambers’, 192, St. Mary’s Road, Alwarpet, Chennai - 600 018. INDIA. : 91 (044) 66229000 ● Fax: 91 (044) 66229011 / 66229012 E-mail: contact@hoec.com ● Website: www.hoec.com CIN: L11100GJ1996PLC029880 August 10, 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: Earnings Call Invite The Earnings Call Invite with respect to the unaudited financial results of the Company for the quarter ended June 30, 2026 is enclosed. We request you to kindly take the same on record. Thanking you, Yours Sincerely, For Hindustan Oil Exploration Company Limited G. Josephin Daisy Company Secretary & Compliance Officer Encl.: a/a Registered Office: ‘HOEC HOUSE’, Tandalja Road, Off Old Padra Road, Vadodara - 390 020. INDIA. : 91 (0265) 2330766 ● E-mail: contact@hoec.com ● Website: www.hoec.com HOEC.com | NSE: HINDOILEXP | BSE:500186 | ISIN: INE345A01011 | SECTOR: OIL EXPLORATION & PRODUCTION Hindustan Oil Exploration Company Ltd. Earnings Conference Call | Q1 FY27 Hindustan Oil Exploration Company Ltd. Q1 FY27 Earnings Conference Call on August 13, 2026 at 03:00 PM IST Chennai, India (August 10, 2026) – Hindustan Oil Exploration Company Ltd, one of the pioneer private players in the Indian Oil & Gas E&P sector, will host an Earnings Conference Call on August 13, 2026 (Thursday) at 03:00 PM IST to discuss financial results for the quarter ended June 30, 2026. Conference Call Details Day, Date Thursday; August 13, 2026 Time 03:00 PM IST Primary Number +91 22 6280 1107 / +91 22 7115 8008 International Toll-Free Numbers USA - 18667462133 UK - 08081011573 Singapore - 8001012045 Hong Kong - 800964448 Pre-Registration Click here to pre-register for the call and dial in directly without (Express Join with DiamondPassTM to avoid waiting for the operator. long queue and save time) Management Represented by: • Mr. Baroruchi Mishra – Managing Director & CEO • Mr. Allen Joseph Andrade – Chief Financial Officer About Hindustan Oil Exploration Company Ltd. Hindustan Oil Exploration Company Limited (HOEC) is one of the pioneer private players in India’s Oil & Gas Exploration and Production (E&P) sector. HOEC holds a diverse portfolio comprising 10 oil and gas blocks with discovered resources and one exploratory block, strategically located across four of the seven producing basins in India. With over four decades of rich sectoral experience, HOEC's vision is to establish and transform resources into assets and unlock value for all its stakeholders. For more information, please visit: www.hoec.com For details please contact: Ernst & Young (EY LLP) Cyril J. Paul / Saloni Soni P: +91 99206 76610 / 95832 74018 E: cyril.paul@in.ey.com/saloni.soni2@in.ey.com