command line options to mvn

[Marilyn Sander -X \(marilysa - Digital-X, Inc. at Cisco\)]

Is there an environment variable that can be used to pass options to mvn?  I
have found $MAVEN_OPTS, but it appears that any options specified there are
passed straight through to java.  That is no doubt handy, but I'd also like
one for maven itself.  I tried $M2_OPTS and $MVN_OPTS, and neither had any
effect.
 
thanks,
--Marilyn