  We used the Swedish-ESO Submillimeter Telescope (SEST) to search for CO
emission associated with three supernova remnants (SNRs) in the Large
Magellanic Cloud: N49, N132D, and N23. Observations were carried out in the
J=2-1 rotational transition of CO (230.5 GHz) where the half power beamwidth of
the SEST is 23". Molecular clouds were discovered near N49 and N132D; no CO
emission was discovered in the region we mapped near N23. The N49 cloud has a
peak line temperature of 0.75 K, spatial scale of ~7 pc and virial mass of
~30,000 solar masses. The N132D cloud is brighter with a peak temperature of 5
K; it is also larger ~22 pc and considerably more massive 200,000 solar masses.
The velocities derived for the clouds near N49 and N132D, +286.0 km/s and
+264.0 km/s, agree well with the previously known velocities of the associated
SNRs: +286 km/s and +268 km/s, respectively. ROSAT X-ray images show that the
ambient density into which the remnants are expanding appears to be
significantly increased in the direction of the clouds. Taken together these
observations indicate a physical association between the remnants and their
respective, presumably natal, molecular clouds. The association of N49 and
N132D with dense regions of molecular material means that both were likely
products of short-lived progenitors that exploded as core-collapse supernovae.
