Paper Title
Impact of Ownership Concentration on Accounting Voluntary Disclosure Reporting: Evidence From Listed Firms in The Down-Stream Sector of The Nigerian Petroleum Industry

Abstract
This study examines the impact of ownership concentration on Voluntary Disclosure by firms in the downstream sector of the Nigerian petroleum industry over the period of ten years (2001 2010). A sample of seven firms listed on the floor of Nigerian Stock Exchange was studied. The study made use of secondary data generated from annual reports and accounts and the Nigerian Stock Exchange Fact book of the sampled companies. The data was analyzed by means of descriptive statistics and regression analysis using SPSS package (Version 20). The results reveal that ownership concentration being one of the major determinants of corporate governance has significant positive association with the extent of voluntary disclosures. Based on the findings, the study recommends among others: That the oil marketing and distribution companies should encourage concentration of shares to a certain degree, so that managerial influence affecting voluntary disclosure would be offset through the pressure from the block-holders. Key Words- Ownership Concentration, Voluntary Disclosure, Petroleum Industry, Nigeria