Scope of Duties and Responsibilities of the Board of Directors

The Board of Directors, as the leader and the highest governing body of the organization, plays a vital role in overseeing the Company’s operations to ensure sound performance, credibility among shareholders and stakeholders, the best interests of the Company, and the sustainable creation of corporate value. The duties of the Board of Directors are as follows:

  1. The Board of Directors has the authority, duties and responsibilities to manage the Company in compliance with laws, the Company’s objectives and Articles of Association, the resolutions of the Board of Directors, and the resolutions of shareholders’ meetings. In this regard, the Board of Directors shall exercise judgement and due care in making business decisions and perform its duties with responsibility, integrity and prudence in order to safeguard the best interests of the Company and its shareholders.
  2. Determine the Company’s vision, mission, strategies, business policies and operational direction, and supervise management to ensure effective and efficient implementation of the prescribed policies, with a view to maximizing value for the Company and its shareholders while taking into account all relevant stakeholders. The Board shall also review and monitor operating results to ensure achievement of the established objectives.
  3. Recognize the roles, duties and responsibilities of the Board as the leader of the organization in defining the Company’s objectives and key goals, and promote and oversee operations relating to Environmental, Social and Governance (ESG) matters in order to create balanced and sustainable value for the Company, stakeholders and society.
  4. Establish the Company’s corporate governance policy and review it regularly at least once a year.
  5. Consider and approve the roles and duties of various sub-committees, as well as any material changes affecting the performance of the appointed sub-committees, as appropriate and for the benefit of the Company.
  6. Appoint, remove and delegate authority and duties to advisors to the Board of Directors, various sub-committees, and the Managing Director for implementation.
  7. Consult experts or advisors of the Company, if any, or engage external advisors or experts when necessary, at the Company’s expense.
  8. Delegate authority to the Management, executive-level employees of the Company, or any other person to act on its behalf within the scope of authority and responsibilities of the Board of Directors.
  9. Approve investments in, and the disposal of, equity securities and/or debt securities.
  10. Approve the provision of guarantees for credit facilities granted to companies having a business relationship with the Company in its capacity as a shareholder.
  11. Approve the establishment, amalgamation, or dissolution of subsidiaries.
  12. Propose to the shareholders the increase or reduction of the Company's registered capital, changes in the par value of shares, and amendments or changes to the Company's Memorandum of Association, Articles of Association, and/or objectives.
  13. Consider the appointment and removal of the Company Secretary by selecting a person with appropriate qualifications, knowledge, capabilities, and experience to support the performance of the Board of Directors' duties, as well as determine the scope of authority, duties, and responsibilities of the Company Secretary.
  14. Consider and approve related-party transactions, except where such transactions are required to be approved by the shareholders' meeting. Such consideration and approval shall be in accordance with the notifications, regulations, and/or rules of the Stock Exchange of Thailand and other applicable regulations.
  15. Oversee and supervise the management and operations of the Company and its subsidiaries to ensure compliance with the Company's policies, securities laws, as well as the notifications, regulations, and rules of the Capital Market Supervisory Board, the Securities and Exchange Commission (SEC), and the Stock Exchange of Thailand (SET), including, but not limited to, related-party transactions and the acquisition or disposal of material assets, to the extent that such matters are not inconsistent or in conflict with other applicable laws. The Board shall also ensure that adequate and appropriate internal control and internal audit systems are established and maintained.
  16. The Board of Directors shall ensure that the Company has appropriate risk management and internal control systems, together with an effective internal audit system, particularly with respect to transactions in which directors have a conflict of interest, in accordance with applicable laws and the requirements of the Stock Exchange of Thailand.
  17. The Board of Directors should oversee and monitor the establishment of clear policies and practices on anti-corruption and ensure that such policies and practices are communicated at all levels of the organization and to external parties to promote effective implementation.
  18. The Board of Directors shall ensure that channels are provided for receiving complaints and whistleblowing reports concerning misconduct or inappropriate actions, together with appropriate measures to protect whistleblowers.
  19. The Board of Directors should establish an enterprise-level information technology governance and management framework that is aligned with the Company's business needs and oversee the effective use of information technology to enhance business opportunities and improve operations, as well as consider and determine key information technology risks.
  20. The Board of Directors is responsible for ensuring that the Company's financial reporting and disclosure of material information are accurate, adequate, timely, and in compliance with applicable rules, standards, and relevant practices.
  21. Ensure the preparation of sustainability information in accordance with applicable standards, review and approve the sustainability report, and approve the annual registration statement/annual report (Form 56-1 One Report).
  22. Ensure the preparation of a Succession Plan to continuously and appropriately prepare and develop personnel with potential to succeed in key positions of the Company.
  23. Conduct an annual performance evaluation of the Board of Directors, sub-committees and individual directors, and promote the continuous development of directors’ knowledge and capabilities.

The delegation of authority, duties and responsibilities by the Board of Directors shall not constitute a delegation or sub-delegation of authority that would enable the Board of Directors or any person authorized by the Board of Directors to approve any transaction in which such person or any person who may have a conflict of interest (as defined in the notifications of the Securities and Exchange Commission or the Capital Market Supervisory Board) may have an interest, may derive any benefit, or may otherwise have a conflict of interest with the Company or its subsidiaries, except for the approval of transactions in accordance with the policies and criteria approved by the shareholders’ meeting or the Board of Directors.

The Board of Directors shall understand the scope of its duties and delegate management authority of the Company to the President and management in writing. Nevertheless, such delegation shall not relieve the Board of Directors of its duties and responsibilities. The Board of Directors shall monitor and oversee management to ensure that duties are performed in accordance with the authority delegated.

Updated as of 22 September 2026

The Board of Directors, in collaboration with Management, shall undertake the following matters:

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Matters to be carried out

These include matters for which the Board of Directors is mainly responsible for ensuring that they are carried out properly. The Board of Directors may delegate the management to propose the following matters to the Board of Directors for consideration:

  • Determination of objectives and main goals of business operations;
  • Creation of corporate culture which adheres to ethics and acting as a role model;
  • Supervision of composition and performance of the Board of Directors to efficiently achieve the defined objectives and main goals of business operations.
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Matters to be carried out in collaboration with the management

These include matters to be carried out collectively by the Board of Directors, the Chief Executive Officer, and the management. The management will propose the matters to the Board of Directors for approval while the Board of Directors ensures that the overall policy is in line with the defined objectives and main goals of business operations and will delegate the management to execute. The management shall then report to the Board of Directors regularly. These matters are:

  • Determination and review of annual strategies, goals, and business plans;
  • Oversight of suitability and sufficiency of risk management and internal control;
  • Determination of authority that are suitable for the responsibilities of the management;
  • Determination of resources allocation framework, development, and budgeting such as policy and plan for people management and information technology management policy;
  • Monitoring and assessment of performance;
  • Oversight over reliable financial disclosure and reporting and sufficient and appropriate non-financial disclosure.

Matters that should not be undertaken by the Board of Directors

These include the following matters that the Board of Directors may only supervise at the policy level and will delegate the Chief Executive Officer and the management to take the main responsibility in carrying out:

  • Execution of strategies, policies, and plans approved by the Board of Directors. The Board of Directors should allow the management to take the responsibilities in making decisions on operations, procurements, recruitments, etc. following the defined framework. The Board of Directors should only exercise oversight over these matters without interfering with the decisions of the management except in the case where it is necessary to do so.
  • Matters which are subject to restrictions such as the approval for matters in which Directors have an interest.

In determining annual strategies and work plans, the Board of Directors will ensure that environmental considerations and relevant risk factors on the stakeholders throughout the value chain including such other factors which could affect the achievement of main goals of the Company are analyzed and that there shall be a mechanism to allow the Board of Directors to understand the need of stakeholders truly.

COMPOSITION AND APPOINTMENT OF THE BOARD OF DIRECTORS OF STA

The following is a summary of the composition, appointment, removal or retirement from the Board of Directors of STA set forth in the Articles of Association of STA:

  1. The number of members of the Board of Directors of STA shall be determined by a shareholders meeting but shall be not less than five persons and not less than one-half of the total number of Directors must reside in the Kingdom of Thailand.
  2. Of the total number of Board members, at least one-third and no fewer than three persons must be independent directors;
  3. The number of members of the Board of Directors of STA shall be determined by a shareholders meeting but shall be not less than five persons and not less than one-half of the total number of Directors must reside in the Kingdom of Thailand.
    • Each shareholder shall have one vote for one share.
    • A shareholder must use all of his/her votes in (1) to elect one or several persons as Director or Directors, however, he or she may not split his/her votes unequally between any person in any number.
    • The persons who receive the most votes shall be elected as Directors, in the number of Directors required or to be elected on the relevant occasion. In the event that votes of two or more nominees are equal in number, causing the number of Directors required or to be elected on such relevant occasion to be exceeded, the chairman of the meeting shall have a casting vote.
  4. At every annual general meeting, one-third of the Directors, or, if the number of Directors is not a multiple of three, then the number nearest to one-third, shall retire from office. The Directors who are to retire from office in the first and the second years after registration of the Company shall be drawn by lots. In subsequent years, the Directors who have been holding office for the longest time shall retire.
  5. Any Director wishing to resign from office shall submit his or her resignation letter to STA. The resignation shall be effective from the date on which STA receives the resignation letter.
  6. The shareholders meeting may pass a resolution to remove any Director from office prior to rotation, by a vote of not less than three-fourths of the number of the shareholders attending the meeting and having the right to vote, and whose shares represent a total of not less than one half of the number of shares held by the shareholders attending the meeting and having the right to vote.

The Board currently comprises twelve Directors, four of whom are Independent Directors. The Company has eight Executive Directors and four Non-executive Directors. The composition of the Board takes into consideration the nature and scope of the Group’s operations to allow constructive discussion on the basis of board diversity in terms of knowledge, skills, experiences, ages, and genders of directors bringing about the reasonable decision making. In this regard, STA’s directors have invaluable experience in accounting, finance, business management, strategic planning, marketing, law and the rubber industry in order to perform their duties effectively.