[en] Velocity correlations of intermediate mass fragments (IMFs), produced in central collisions of Au + Au at 150 A.MeV beam energy, are extracted from measurements with the FOPI (phase I) detector system at SIS in GSI Darmstadt. The IMF correlation function for semicentral events is found to be affected by the directed sideward flow. When rotating the events into a unique reaction plane an enhancement of correlations, resulting from event mixing effects, vanishes. Selecting violent collisions with a high degree of azimuthal symmetry the correlation function appears nearly independent of additional event or single particle gate conditions. The comparison of the data with a Coulomb dominated final-state interaction model points to time scales of τ ∝ 25 fm/c or less for emitting IMFs from an expanding and multifragmenting source with radius R ∝ 14 fm. (orig.)