The problem of computing a matching of maximum weight in a given edge-weigh
ted graph is not known to be P-hard or in RNC. This paper presents two para
llel approximation algorithms for this problem. The first is an RNC-approxi
mation scheme, i.e., an RNC algorithm that computes a matching of weight at
least 1 - epsilon times the maximum for any fixed constant epsilon > 0. Th
e other is an NC approximation algorithm achieving an approximation ratio o
f 1/(2 + epsilon) for any fixed constant epsilon > 0. (C) 2000 Elsevier Sci
ence B.V. All rights reserved.