Progress in Major Investment

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take noresponsibility for the contents of this announcement, make no representation as to its accuracyor completeness and expressly disclaim any liability whatsoever for any loss howsoever arisingfrom or in reliance upon the whole or any part of the contents of this announcement. DATANG INTERNATIONAL POWER GENERATION CO. LTD (a sino-foreign joint stock limited company incorporated in the People's Republic of China) (Stock Code: 00991) OVERSEAS REGULATORY ANNOUNCEMENT AND INSIDE INFORMATION ANNOUNCEMENT AND ANNOUNCEMENT ON PROGRESS IN MAJOR INVESTMENT Special Notice: The board of directors (the "Board") and all directors (the "Directors") of the Company warrantthat there are no false representations and misleading statements contained in, or materialomissions from, this announcement, and severally and jointly accept the responsibility for thetruthfulness, accuracy and completeness of the contents of this announcement. This announcement is made by the Company pursuant to the Inside Information Provisions (asdefined under the Rules Governing the Listing of Securities on The Stock Exchange of Hong KongLimited (the "Listing Rules")), under Part XIVA of the Securities and Futures Ordinance(Cap. 571, Laws of Hong Kong) and Rules 13.09(2)(a) and 13.10(B) of the Listing Rules. Inner Mongolia Datang International Keshiketeng Qi coal-based natural gas and ancillary gastransmission pipelines project (the "Keqi Coal-based Gas Project" or the "Project") wasapproved by the National Development and Reform Commission (the "NDRC") on 20 August 2009,being the first large-scale coal-based natural gas pilot project approved by the NDRC. InnerMongolia Datang International Keshiketeng Qi Coal-based Gas Company Limited (the "KeqiCoal-based Gas Company"), a subsidiary of Datang Energy and Chemical Company Limited (the"Energy and Chemical Company"), which is a wholly-owned subsidiary of Datang InternationalPower Generation Co., Ltd. (the "Company"), is responsible for the development and constructionof the Project. The Project will be constructed in three series, with an annual productioncapacity of 4 billion cubic meters of natural gas. Currently, the Series 1 of the KeqiCoal-based Gas Project has gone through all technological process, and has all ancillarytransmission pipelines connected; the Project is undergoing test-running and fine-tuningprocesses and will commence production in the near future. The coal-based natural gas produced by the Keqi Coal-based Gas Project will be supplied tothe Beijing market through the "Keshiketeng Qi ?Gubeikou Gas Transmission Pipeline - meteringstation in Bakeshiying"; the related company of natural gas sales branch of PetroChina CompanyLimited (the "PetroChina Natural Gas Sales Company" or the "Buyer") will receive the coal-basedgas from the metering station in Bakeshiying, Luanping County, Hebei Province through the"Exclusive Natural Gas Pipeline of No.4 Shaanxi-Beijing Pipeline", and these will then betransmitted to users in Beijing. On 10 December 2013, Datang Energy and Chemical Marketing Company Limited (the "Energy andChemical Marketing Company" or the "Seller"), a wholly-owned subsidiary of the Company,entered into the Coal-based Natural Gas Sale and Purchase Agreement (the "Agreement") withPetroChina Natural Gas Sales Company, the major terms of which are as follows: 1. Term: The Agreement shall become effective when it is duly signed by the authorised representatives of both parties with their respective company seals affixed thereto, and shall remain effective until 31 December 2043. 2. Supply Capacity: As the Keqi Coal-based Gas Project is divided into three stages, namely the trial-run period (120 days from the date of commencement of gas supply), the ramp-up period (from the end of the trial-run period of "Project Series 1" to the end of the trial-run period of "Project Series 3") and the stable peak production period (from the end of ramp-up period to the expiry date the Agreement or the date of termination prior to its expiration), the annual contractual amount of the Series 1 and 2 of the ramp-up period are 1.2 billion cubic meters/year and 2.5 billion cubic meters/year respectively, and that of the stable peak production period is 4.0 billion cubic meters/ year. 3. Pricing principles: (1) The initial transaction price (the "contractual price") is RMB2.75 per cubic meter (including 13% VAT). (2) The contractual price is based on the coal-based natural gas with lower calorific value of not lower than 8,000kCal/m3. If the lower calorific value of the coal-based natural gas delivered by the Seller is lower than 8,000kCal/m3 on any day during the term of the Agreement, the contractual price applied in the actual settlement shall be discounted as follows: Discounted contractual price = contractual price x (the average calorific value of coal-based natural gas on that particular day/8,000). (3) The abovementioned contractual price shall be valid for the period from the date of entering into the Agreement to 31 December 2016. The contractual price applicable for 1 January 2017 and onwards can be adjusted according to pricing and market conditions. (4) If the State requires or recommends natural gas to be measured in calorific value, both parties agreed that the contractual price shall be calculated based on the calorific value in accordance with the requirement of the State and the principles stated in the Agreement. Upon commencement of production, Keqi Coal-based Gas Project will further enhance the Company'scompetitiveness and profitability, at the same time effectively relieving the supply pressure ofnatural gas in Beijing, thereby contributing to the implementation of energy strategies of theState, the development of Beijing and the "Blue Sky Campaign". By Order of the Board Zhou Gang Secretary to the Board Beijing, the PRC, 10 December 2013 As at the date of this announcement, the Directors of the Company are: Chen Jinhang, Hu Shengmu, Cao Jingshan, Fang Qinghai, Zhou Gang, Li Gengsheng, Cao Xin,Cai Shuwen, Liu Haixia, Guan Tiangang, Dong Heyi*, Ye Yansheng*, Li Hengyuan*, Zhao Jie*,Jiang Guohua* * Independent non-executive Directors