  A search is performed in symmetric 3-jet hadronic Z decay events for evidence
of colour singlet exchange and for colour reconnection effects predicted by the
Rathsman model. Asymmetries in particle flow and the angular separation of
particles are found to be sensitive to such effects.
  95% upper limits of 7-9% are found for the fraction of colour singlet
exchange, and of 0.93% for the colour reconnection parameter $R_0$ (default
value 0.1) of the Rathsman model.
