We search for signatures of planets in 43 intensively monitored microlensin
g events that were observed between 1995 and 1999. Planets would be expecte
d to cause a short-duration (similar to1 day) deviation on the smooth, symm
etric light curve produced by a single lens. We find no such anomalies and
infer that less than one-third of the similar to0.3 M. stars that typically
comprise the lens population have Jupiter mass companions with semimajor a
xes in the range of 1.5 AU < a < 4 AU. Since orbital periods of planets at
these radii are 3-15 yr, the outer portion of this region is currently diff
icult to probe with any other technique.