  We investigate the problem of extracting a static potential between a quark
and its antiquark in a quark-gluon plasma (QGP) from lattice-QCD computations
of the singlet free energy, $F_{Q\bar{Q}}(r)$. We utilize the thermodynamic
$T$-matrix formalism to calculate the free energy from an underlying potential
ansatz resummed in ladder approximation. Imaginary parts of both $Q\bar Q$
potential-type and single-quark selfenergies are included as estimated from
earlier results of the $T$-matrix approach. We find that the imaginary parts,
and in particular their (low-) energy dependence, induce marked deviations of
the (real part of the) potential from the calculated free energy. When fitting
lattice results of the latter, the extracted potential is characterized by
significant long-range contributions from remnants of the confining force. We
briefly discuss consequences of this feature for the heavy-quark transport
coefficient in the QGP.
