Report on the last Exercise of STEC-W No.18 (Amendment)

Ref: ST/010/2007/0037 June 6 th, 2007 Re: Report on the last Exercise of Warrants (STEC-W No.18/2007) (Amendment) To: The President The Stock Exchange of Thailand Sino-Thai Engineering & Construction Public Company Limited would like to amendment the report on the exercise of STEC-W No.18 and on May 30th , 2007 because there is a shareholder who was not exercise his warrants in a hold amount. Therefore, the number of warrants being exercised must change from 1,076,690 units to 1,049,690 units and the total remaining warrants listed in the Stock Exchange of Thailand must change from 215,920 units to 242,920 units as per following details: - Exercising ratio: 1 unit of warrant per 1 ordinary share. - Exercising price of STEC- W : Baht 1 per share. - Ordinary shares reserved to support the exercise of STEC-W: 1,292,610 shares. - No. of STEC-W holders exercise: 140 - No. of warrants being exercised of STEC-W No.18/2007: 1,049,690 units. - Ordinary shares resulted from the exercise of STEC-W No.18/2007: 1,049,690 shares. - Money received from the exercise of STEC-W No.18/2007: 1,049,690 Baht. - Total remaining warrants listed in the Stock Exchange of Thailand of STEC-W: 242,920 units. STEC-W expired and could not be used since May 31st,2007. Please be informed accordingly. Yours sincerely, Mr. Woraphant Chontong SEVP. Financial and Administration Division