In pursuit of the objective of evaluating the performance of the national industrial segments, composed of publicly traded companies, in light of Brazilian and world economic activity level, the present dissertation attempts to contribute to the development of forecast models intended to aid managers and investors in the decision making process. The relationship between several levels of profit, shown as Net Sales, Gross Profit, Operating Profit and Net Profit achieved by the national industrial segments, composed of listed companies negotiated on São Paulo Stock Exchange, and the level of economic activity, represented by the national and global GDP measured through the period comprised between January 1996 and December 2002 on a quarterly basis, was studied. The first part is dedicated to analyzing the elasticity of several levels of profit of the segments evaluated in terms of the GDP variations. The second part analyses the correlation rate between the global GDP and the performance of the industrial segments. Considerable collinearity was identified between the national GDP and the global GDP, invalidating the use of these two variables simultaneously in order to evaluate the performance of the industrial segments. During the last part, an attempt was made to include other macro economic variables, in order to obtain more explanatory power of the performance of the segments in light of the variations of the level of national economic activity. Considering the statistic significance level obtained during these tests, the potential of using these relations in a forecast model was proved.