Report on the Exercise of Warrants No.5/2004

Ref: ST/010/2004/0018 March 31, 2004 Re: Report on the Exercise of Warrants No.5/2004 To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to report the exercise of warrants (STECON-W) no.5 on March 30, 2004 As per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share - Exercising price: Baht 1 per share - Ordinary shares reserved to support the exercise: 8,362,650 shares - No. of warrant holders exercise: 14 - No. of warrants being exercised: 294,500 units - Ordinary shares resulted from the exercise: 294,500 shares - Money received from the exercise: Baht 294,500 - Total remaining warrants listed in the Stock Exchange of Thailand: 8,067,850 units Please be informed accordingly. Yours sincerely, Mr. Woraphant Chontong (SVP.) Finance & Accounting Division