Motiva？？es determinantes para a recompra de a？？es: um estudo empírico no mercado de a？？es brasileiro no período de 1995 a 2008

the objective of this work was to verify the determining reasons for brazilian companies to repurchase shares in the period from 1995 to 2008. the explanatory variables used in the statistical tests were based on previous studies (durand, 1952; jensen; meckling, 1976; spence, 1973). the data were obtained from the economática database and the empirical tests consisted of multiple regression with pooled data, with the help of least squares and tobit methods. pooled and tobit regressions were applied to verify the statistical robustness of the results. the study was based on the capital structure adjustment, agency, dividend substitution and signaling theories. the reasons for share repurchases tested were adjustment of the capital structure, reduction of available cash flow, substitution of dividend payments and firm undervaluation. the only statistically significant reason for share buybacks was reduction of available cash flow. in light of agency theory, this indicates that firms with available cash can repurchase their shares with the intention of minimizing the principal-agent conflict.