---

The influence corporate governance variables including: abnormal accruals, board independent directors and institutional investors ownerships ratio on the cost of equity capital have been examined. The examine of research hypothesis was done by multiple regression analysis by the use of general least squared (GLS) method, to the 65 selected companies accepted by Tehran Stock Exchange for the time period of 2004-2008 and by pannel data. The research- results indicate that among the corporate governance variables, abnormal accruals and board independent directors ratios have respectively positive and negative meaningful relationship with the cost of equity capital. .

---

---

Achieving economic growth requires an optimal allocation system of resources at national level. This is not possible without a perfect and efficient financial market. The stock exchange as a part of capital market can provide the required national financial resources and lead to economic growth. In the capital market, information is regarded as the most valuable asset. The more the transparency of information in the stock exchange, the lower the information asymmetry and the more efficient capital market will be. This study aims to analyze the effects of the ownership share of institutional investors, the board size, the role of non-executive board and separation of chief executive officer and chairman of the board roles (separation variable) on information asymmetry in the stock exchange. It estimates a panel data regression for the companies listed in the Tehran Stock Exchange (TSE) during the fourth national development plan. The results indicate that the ownership share of institutional investors and board size have negative effects on information asymmetry, while the ratio of non-executive members to board size and separation variable have no significant effects on information asymmetry. 

---

Corporate governance has defined as a set of regulations and assessment of corporate operation to balance between stakeholder's interests and to guide company's policies toward maximum level of efficiency and profitablity. In this broad sense, corporate governance complies with rules governing running firms.in the narrow sense, corporate governance refers to requirements for governing and accounting public companies that has been introduced after major American corporates scandal which resulted to ratification of Sarbanes-Oxley Act in 2002. Studies show, corporate governance requirements can be categorized in three groups: requirements for governing corporation, requirements for accounting and requirements for protection of minority shareholders.
In this study, we introduce requirements for corporate governance (in the narrow sense) and compare Iranian laws and regulations with US and UK. As a result, we found that although there is some regulation for registered public companies in Iran's capital market in this issue, but Iranian law hasn't fulfilled all necessary requirements for better corporate governance. Hence, we suggested some modifications in Iranian commercial code.
 

---

E-business Governance is the decision-making framework within which decisions about relationship, accountability, compliance, direction, and control in e-business activities are made. This structure make the e-commerce organization manage itself more effectively and prevent failure that take place by having not adequate attention to governing elements, risk of e-business, dynamic of standards, and rules. In this research by using literature review and interviews with experts, a questionnaire was designed and by analyzing the gathered data through surveys, the   e-business key success factors such as e-business enablers, corporate and IT governance, the best practices, management and strategy were extracted. Then these key factors were presented as the e-business governance models. The results of statistical analysis confirm that the model might be helpful in handling the process of e-business in Iran.
 

---

The purpose of this study is to investigate the relationship between organizational trust types and brand performance with the mediation role of corporate governance in companies admitted to Tehran Stock Exchange. This is an applied research and in terms of method is descriptive- correlational. The statistical population of this research is the companies accepted in Tehran Stock Exchange. A sample of 138 companies was selected and the research questionnaire was completed by senior managers of these companies. Of these, 95 questionnaires were analytic. Then, the relationship between the variables of the research was tested using the SmartPls software and the structural equation modeling. The findings of the research show that there is a positive and significant relationship between knowledge-based trust and identification-based trust with corporate governance, but the relationship between deterrence-based trust and corporate governance is negative. The positive and significant relationship between corporate governance and brand performance was also confirmed. Also, the results of the research show that corporate governance has a mediating role between the types of organizational trust and brand performance of the companies accepted in Tehran Stock Exchange.