  The system created in non-central relativistic nucleus-nucleus collisions
possesses large orbital angular momentum. Due to spin-orbit coupling, particles
produced in such a system could become globally polarized along the direction
of the system angular momentum. We present the results of Lambda and
anti-Lambda hyperon global polarization measurements in Au+Au collisions at
sqrt{s_NN}=62.4 GeV and 200 GeV performed with the STAR detector at RHIC. The
observed global polarization of Lambda and anti-Lambda hyperons in the STAR
acceptance is consistent with zero within the precision of the measurements.
The obtained upper limit, |P_{Lambda,anti-Lambda}| <= 0.02, is compared to the
theoretical values discussed recently in the literature.
