CHYY Development Group Limited — Proxy Solicitation & Information Statement 2026

Jun 2, 2026

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

中國恒有源發展集團有限公司

CHYY DEVELOPMENT GROUP LIMITED

(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 8128)

NOTICE OF ANNUAL GENERAL MEETING

NOTICE IS HEREBY GIVEN that the annual general meeting (the "Annual General Meeting") of CHYY DEVELOPMENT GROUP LIMITED (the "Company") will be held at 8/F., Chung Hing Commercial Building, 62-63 Connaught Road Central, Central, Hong Kong on Friday, 26 June 2026 at 11:00 a.m. for the following purposes:

ORDINARY RESOLUTIONS

1. To receive and consider the audited financial statements of the Company for the year ended 31 December 2025 together with the reports of the directors of the Company (the "Directors") and the auditors of the Company thereon.
2. (a) To re-elect Mr. Xu Shengheng as executive Director and to authorise the board of Directors to fix his remuneration;
   (b) To re-elect Mr. Dai Qi as executive Director and to authorise the board of Directors to fix his remuneration; and
   (c) To re-elect Mr. Liao Yuan as non-executive Director and to authorise the board of Directors to fix his remuneration.
3. To re-appoint the auditors of the Company and to authorise the board of Directors to fix their remuneration.
4. To consider and, if thought fit, to pass the following resolutions as ordinary resolutions:

A. "THAT:

(a) subject to paragraph (c) of this resolution, and pursuant to the Rules (the "GEM Listing Rules") Governing the Listing of Securities on the GEM (the "GEM") of The Stock Exchange of Hong Kong Limited (the "Stock Exchange"), the exercise by the Directors during the Relevant Period (as defined below) of all the powers of the Company to allot, issue and deal with additional shares in the share capital of the Company (the "Shares") (including any sale or transfer of treasury

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Shares out of treasury), and to make or grant offers, agreements and options which might require the exercise of such powers be and is hereby generally and unconditionally approved;

(b) the approval in paragraph (a) of this resolution shall authorise the Directors during the Relevant Period to make or grant offers, agreements and options which might require the exercise of such powers after the end of the Relevant Period;

(c) the total number of the Shares allotted or agreed conditionally or unconditionally to be allotted (whether pursuant to an option or otherwise) by the Directors pursuant to the approval in paragraph (a) of this resolution otherwise than pursuant to (i) a Rights Issue (as defined below); or (ii) any issue of the Shares upon the exercise of existing warrants to subscribe for the Shares or the exercise of options granted under any share option scheme adopted by the Company; or (iii) any scrip dividend or similar arrangement providing for allotment of shares in lieu of the whole or part of a dividend on Shares of the Company in accordance with the Memorandum and Articles of Association of the Company in force from time to time, shall not exceed 20% of the total number of the Shares of the Company in issue (excluding any treasury Shares) as at the date of passing of this resolution, and the authority pursuant to paragraph (a) of this resolution shall be limited accordingly;

(d) if, after the passing of this resolution, the Company conducts a Share consolidation or subdivision, the number of Shares subject to the limit set out in paragraph (c) above shall be adjusted to the effect that the number of Shares subject to the limit set out in paragraph (c) above as a percentage of the total number of issued Shares (excluding any treasury Shares) at the date immediately before and after such consolidation or subdivision shall be the same; and

(e) for the purposes of this resolution:

“Relevant Period” means the period from the date of the passing of this resolution until whichever is the earliest of:

(i) the conclusion of the next annual general meeting of the Company;

(ii) the expiration of the period within which the next annual general meeting of the Company is required by the Memorandum and Articles of Association of the Company, or any applicable law of the Cayman Islands to be held; and

(iii) the date on which the authority given to Directors by this resolution is revoked or varied by an ordinary resolution by shareholders of the Company in general meeting.

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"Rights Issue" means an offer of Shares, or offer or issue of warrants, options or other securities giving rights to subscribe for Shares open for a period fixed by the Directors to holders of Shares on the register on a fixed record date in proportion to their then holdings of Shares (subject to such exclusion or other arrangements as the Directors may deem necessary or expedient in relation to fractional entitlements, or having regard to any restrictions or obligations under the laws of, or the requirements of, or the expense or delay which may be involved in determining the existence or extent of any restrictions or obligations under the laws of, or the requirements of, any jurisdiction applicable to the Company, or any recognised regulatory body or any stock exchange applicable to the Company).

B. “THAT:

(a) subject to paragraph (c) of this resolution, the exercise by the Directors during the Relevant Period (as defined above) of all the powers of the Company to repurchase its Shares on GEM or any other stock exchange on which the Shares of the Company have been or may be listed and recognised by the Securities and Futures Commission of Hong Kong and the Stock Exchange under the Hong Kong Code on Share Buy-backs for such purposes, and otherwise in accordance with all applicable laws and the requirements of the GEM Listing Rules as amended from time to time or that of any other stock exchange, be and is hereby generally and unconditionally approved;

(b) the approval in paragraph (a) of this resolution shall authorise the Directors to procure the Company to repurchase its Shares at such price as the Directors may at their discretion determine in accordance with all applicable laws and regulations;

(c) the Shares of the Company to be repurchased by the Company pursuant to the approval in paragraph (a) of this resolution during the Relevant Period shall not exceed 10% of the total number of the issued Shares of the Company (excluding any treasury Shares) as at the date of passing this resolution, and the authority pursuant to paragraph (a) of this resolution shall be limited accordingly;

(d) if, after the passing of this resolution, the Company conducts a Share consolidation or subdivision, the number of Shares subject to the limit set out in paragraph (c) above shall be adjusted to the effect that the number of Shares subject to the limit set out in paragraph (c) above as a percentage of the total number of issued Shares (excluding any treasury Shares) at the date immediately before and after such consolidation or subdivision shall be the same; and

(e) for the purpose of this resolution, “Relevant Period” shall have the same meanings as ascribed to it under paragraph (d) of resolution numbered 4A of the notice convening this Annual General Meeting.

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C. “THAT conditional upon the passing the resolutions numbered 4A and 4B as set out in the notice convening the Annual General Meeting, the total number of the Shares of the Company which are repurchased by the Company pursuant to and in accordance with resolution numbered 4B shall be added to the total number of the Shares of the Company that may be allotted or agreed conditionally or unconditionally to be allotted by the Directors pursuant to and in accordance with resolution numbered 4A.”

SPECIAL RESOLUTION

1. To consider and, if thought fit, pass the following resolution (with or without amendments) as special resolution:

“THAT subject to and conditional upon the approval of the Registrar of Companies in the Cayman Islands having been obtained, the name of the Company be changed from “CHYY DEVELOPMENT GROUP LIMITED 中國恒有源發展集團有限公司” to “Sino Energy Conservation International Limited 中華節能國際有限公司”, and that any one or more of the Directors or the company secretary of the Company be and are hereby authorised to do all such acts, deeds and things and execute all such documents and make all such arrangements as he/she/they consider necessary, desirable or expedient for the purpose of, or in connection with, the implementation of and giving effect to the above proposed change of company name, and to attend to any necessary registration and/or filing for and on behalf of the Company.”

By order of the Board

CHYY DEVELOPMENT GROUP LIMITED

Xu Shengheng

Joint Chairman

Hong Kong, 3 June 2026

Notes:

1. Any member of the Company entitled to attend and vote at the Annual General Meeting is entitled to appoint one or more proxies to attend and vote instead of him. A proxy need not be a member of the Company.

2. A form of proxy for the Annual General Meeting is enclosed. In order to be valid, a form of proxy, together with the power of attorney or other authority (if any) under which the form is signed, or a certified copy of such power of attorney or authority, must be deposited at the Company’s branch share registrar in Hong Kong, Computershare Hong Kong Investor Services Limited at 17M Floor, Hopewell Centre, 183 Queen’s Road East, Wanchai, Hong Kong not less than 48 hours before the time fixed for the holding of the Annual General Meeting or any adjournment thereof.

3. Completion and return of the form of proxy will not preclude a member of the Company from attending and voting in person at the Annual General Meeting and in such event, the form of proxy shall be deemed to be revoked.

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1. The register of members of the Company will be closed from Tuesday, 23 June 2026 to Friday, 26 June 2026, both days inclusive, during which period no Share transfers will be registered. In order to be eligible to attend and vote at the Annual General Meeting, unregistered holders of Shares should ensure that all Share transfer documents accompanied by the relevant share certificates must be lodged with the Company's branch share registrar and transfer office in Hong Kong, Computershare Hong Kong Investor Services Limited, at Shops 1712-1716, 17/F, Hopewell Centre, 183 Queen's Road East, Wanchai, Hong Kong for registration not later than 4:30 p.m. on Monday, 22 June 2026.

2. In the case of joint holders of a Share, any one of such joint holders may vote, either in person or by proxy, in respect of such Share as if he/she was solely entitled thereto. If more than one of such joint holders are present at the Annual General Meeting, the vote of the senior who tenders a vote, whether in person or by proxy, shall be accepted to the exclusion of the votes of the other joint holders. For this purpose, seniority shall be determined by the order in which the names stand first in the Register of Shareholders in respect of the joint holding.

3. An explanatory statement containing all information reasonably necessary to enable the members to make an informed decision on the Repurchase Mandate, as required by the GEM Listing Rules and referred to in the Resolution 4B, is set out in Appendix I to the circular of the Company dated 3 June 2026.

4. With reference to Resolution 2 set out in this notice, Mr. Xu Shengheng, Mr. Dai Qi and Mr. Liao Yuan shall retire by rotation at the Annual General Meeting and who, being eligible, will offer themselves for re-election. Details of the retiring Directors proposed to be re-elected as Directors at the Annual General Meeting are set out in Appendix II to the circular of the Company dated 3 June 2026.

5. Pursuant to Rule 17.47(4) of the GEM Listing Rules, any voting at the Annual General Meeting or any adjournment thereof will be taken by poll.

As at the date of this announcement, the Board comprises Mr. Xu Shengheng and Mr. Dai Qi as executive Directors, Mr. Liao Yuan, Ms. Liu Ening and Mr. Zhang Yiying as non-executive Directors, Mr. Zhang Honghai, Mr. Guan Chenghua and Mr. Guo Guanglei as independent non-executive Directors.

This announcement, for which the Directors collectively and individually accept full responsibility, includes particulars given in compliance with the GEM Listing Rules for the purpose of giving information with regard to the Company. The Directors, having made all reasonable enquiries, confirm that to the best of their knowledge and belief the information contained in this announcement is accurate and complete in all material respects and not misleading or deceptive, and there are no other matters the omission of which would make any statement herein or this announcement misleading.

This announcement will remain on the GEM website with the domain name of www.hkexnews.hk on the "Latest Company Announcement" page for at least 7 days from the date of publication and on the website of the Company at www.chyy.com.hk.

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