Answer turned out to be really simple. All I had to do was following:
go to folder with root pom run "grails create-app my-app-name" go to created folder with new grails project and run "grails create-pom my.group.id" Add root pom to grails pom.xml generated by grail' last command as parent Add my other 6 maven modules as dependencies to grails' pom. After running "mvn clean install" on my root pom I checked that generated .war file for my Grails module contains all necessary jars from my other modules.
Well, everything turned out to be so simple. Maven is really great, perhaps this all long question appeared because I just didn't expect it to be that great.