This paper studies an extension of the bilateral gamma process assuming that the drift
coefficient may jump at an exponentially distributed random time. The drift switching
can reflect the symmetry between major economic events and moves of financial market
indexes. The bilateral gamma distribution has an asymmetric form and fits well with
different financial data when there are not external shocks. As the main results, we provide
exact formulas for the probability density and incomplete moment-generating functions of
the stated process. The expressions found are used for risk measurement and European
option pricing. The new formulas are determined in particular by values of the incomplete
gamma, Whittaker and confluent hypergeometric functions. Numerical examples of the
computations are also afforded. The computation time for the formulas is under 4 s in a
compiler compatible with MatLab.