M.A. Thesis:

Ownership Structure, Audit size and firm performance

Abstract The main objective of this research is to investigate the relationship between ownership structure, audit quality and performance of the company in Tehran Stock Exchange. Various tools used to align the interests of managers and owners are called corporate governance tools, which can be referred to as an independent auditor and ownership structure. By separating property from management and maintaining the conflict of interests between owners and managers, evaluating and evaluating the performance of companies and managers is a matter of interest among different strata, such as creditors and landlords. Today, the problem of ownership separation from management reflects how it can be ensured that executives use their freedom to act in the interests of investors. This research was conducted for a 5-year period between 92 and 96 years. The data of the companies were categorized using Excel softwriting software and analyzed using ivyz software. The results of the research showed that there is a positive and significant relationship between the ownership structure and the concentration of ownership and management ownership with the firm's performance, the shareholder combination is an effective factor in the company's performance, since it reflects the adoption of different profitability strategies Also, the auditor's size as an agent for reducing corporate representation problems modifies the relationship between ownership structure (ownership concentration and management ownership) and firm performance, and this moderation is also positive and significant.

Keywords: Corporate Performance, Property Structure, Audit Quality, Management Ownership, Ownership Focus, Auditor's Size