We report the discovery of a third planetary mass companion to the G0 star HD 74156 .
High precision radial velocity measurements made with the Hobby-Eberly Telescope aided the detection of this object .
The best fit triple Keplerian model to all the available velocity data yields an orbital period of 347 days and minimum mass of 0.4 M _ { Jup } for the new planet .
We determine revised orbital periods of 51.7 and 2477 days , and minimum masses of 1.9 and 8.0 M _ { Jup } respectively for the previously known planets .
Preliminary calculations indicate that the derived orbits are stable , although all three planets have significant orbital eccentricities ( e = 0.64 , 0.43 , and 0.25 ) .
With our detection , HD 74156 becomes the eighth normal star known to host three or more planets .
Further study of this system ’ s dynamical characteristics will likely give important insight to planet formation and evolutionary processes .