A new formulation of the Stride of 3 reduction algorithm for block tridiagonal systems is presented. Partial fractions expansions are used for decoupling the tridiagonal systems occurring during the forward reduction and backward substitution processes. As a result enhanced parallelism is obtained in the algorithm. A hybrid combination of Stride reduction and block alternating group explicit method (BLAGE) is shown to have a superior convergence rate than BLAGE and the cyclically reduced BLAGE system.