lib
META-INF
projectA.jar
ProjectB.war

In my case, I was using an MDB so it was needed to be declared as  <**ejbModule**> instead of jarModule. I also had to declare my dependency as of type ejb to be picked up Jboss (6.4):

<dependency>
    <groupId>ab.cd</groupId>
    <artifactId>mdb-publisher</artifactId>
    <version>xxx-SNAPSHOT</version>
   <type>**ejb**</type>
</dependency>