  This letter describes a direct search for pair produced magnetic monopoles in
e+e- collisions. The analysis is based on 62.7 pb^-1 of data collected with the
OPAL detector at an average centre-of-mass energy of sqrt(s)= 206.3GeV. The
monopole signal was assumed to be characterized by two back-to-back particles
with an anomalously high ionization energy loss de/dx in the tracking chambers.
No evidence for production of monopoles was observed. Upper limits were
obtained on the magnetic monopole pair-production cross-section (sigma) in the
mass range 45 GeV/c^2<m_M<102 GeV/c^2. The average limit is sigma < 0.05 pb and
is essentially independent of the magnetic monopole mass. The cross-section
limit is derived at the 95% confidence level and is valid for spin-1/2 magnetic
monopoles.
