  In this paper, we introduce the Birnbaum-Saunders power series class of
distributions which is obtained by compounding Birnbaum-Saunders and power
series distributions. The new class of distributions has as a particular case
the two-parameter Birnbaum-Saunders distribution. The hazard rate function of
the proposed class can be increasing and upside-down bathtub shaped. We provide
important mathematical properties such as moments, order statistics, estimation
of the parameters and inference for large sample. Three special cases of the
new class are investigated with some details. We illustrate the usefulness of
the new distributions by means of two applications to real data sets.
