Please find attached the intimation letter for closure of Trading Window.

HCC/SEC/1 NS I DER/2026 September 28, 2026 BSE Limited National Stock Exchange of India Ltd. The Corporate Relationship Dept, Exchange Plaza, Phiroze Jeejeebhoy Towers, Bandra-Kurla Complex, Dalal Street, Sandra (East), Mumbai-400 001. Mumbai-400 051. Scrip Code : 500185, 974246, 974247 Symbol : HCC 97 4249 & 97 4250 Dear Sir I Madam, Sub : Intimation of closure of Trading Window Pursuant to the Company's Code of Conduct for prevention of Insider Trading, the Trading Window for dealing in the Company's Securities will remain closed from Thursday, October 1, 2026, for all Designated Persons of the Company. The closure is in connection with the declaration of Unaudited Financial Results of the Company for the quarter and six months ending on September 30, 2026. The Trading Window will open 48 hours after the said Financial Results are declared to the Stock Exchanges. We request you to kindly take the above on record. Yours sincerely For Hindustan Construction Company Ltd. Nitesh Kumar Jha Company Secretary Encl.: As above Hindustan Construction Co Ltd Hincon House, LBS Marg, Vikhroli (West), Mumbai -400 083, India Tel: +91 22 2575 1000 Fax: +91 22 2577 7568 www.h ccindia.com CIN : L45200MH1926PLC001228