- Translation - AIS-CP 027/2007 March 26, 2007 Re: Notification of the Book Closing for Amortizing and Interest Payment of Debentures of the Company (AIS07OA) To: The President The Stock Exchange of Thailand Refer to: The Letter No. MKOT.65 - 500509 of Siam Commercial on March 26, 2007 Advanced Info Service Public Company Limited ("the Company") would like to inform you that the Company will close the registered book for amortizing and interest payment of debentures of the Company (AIS07OA), the details are shown in the referenced letter. Please be informed accordingly. Yours faithfully, -signed- Pong-Amorn Nimpoonsawat (Mr.) Chief Finance Officer Advanced Info Service Public Company Limited Reference Letter MKOT.65 - 500509 March 26, 2007 Notification of Book Closed Date for Amortizing and Interest Payment The Stock Exchange of Thailand With reference to Debentures issued by Advanced Info Service Public Company Limited named The Amortizing Debentures of Advanced Info Service Public Company Limited No.4/2002 Due 2007 (AIS07OA) with face value of Baht 1,000 and offering amount at 5,000,000 units "the Debentures" , the Company will pay amortizing and interest on semi annual basis. Interest shall be payable on 21 April and 21 October of each year throughout the term of the Debentures. The Bank as a capacity of Registrar of the Debentures would like to inform that the fourth amortizing and the ninth coupon payment is due on April 23, 2007. Amortizing 200 Baht per unit. Coupon rate is 3.65% per annum. Calculation period is 182 days starting from October 21, 2006 to April 20, 2007. The book closed date of the Debentures is on April 9, 2007 at noon. Please be informed accordingly. Yours faithfully, The Siam Commercial Bank Public Company Limited (Authorized Signatory)