Report on the Exercise of Warrants STEC-W No.17,STEC-W2 No.8

Ref: ST/010/2007/0016 Apirl 2nd, 2007 Re: Report on the Exercise of Warrants (STEC-W No.17/2007, STEC-W2 No.8/2007) To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to report the exercise of STEC-W No.17 and STEC-W2 No.8 on March 30th , 2007 as per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share - Exercising price of STEC- W : Baht 1 per share - Exercising price of STEC- W2 : Baht 8.50 per share - Ordinary shares reserved to support the exercise of STEC-W: 1,806,550 shares, and STEC-W2: 163,548,461 shares - No. of STEC-W holders exercise: 6, STEC-W2 exercise:0 - No. of warrants being exercised of STEC-W No.17/2007: 513,940 units, and STEC-W2 No. 8/2007: 0 unit - Ordinary shares resulted from the exercise of STEC-W No.17/2007: 513,940 shares, and STEC-W2 No.8/2007: 0 share - Money received from the exercise of STEC-W No.17/2007: 513,940 Baht, and STEC-W2 No.8/2007: 0 Baht - Total remaining warrants listed in the Stock Exchange of Thailand of STEC-W:1,292,610 units, and STEC-W2:163,548,461 units Please be informed accordingly. Yours sincerely, Mr. Woraphant Chontong SEVP. Financial and Administration Division