If for some reason a dependency which is declared in the pom of the project needs to be excluded, the excluded flag could be used as follows:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-ear-plugin</artifactId>
<version>2.5</version>
<configuration>
[...]
<modules>
<webModule>
<groupId>artifactGroupId</groupId>
<artifactId>artifactId</artifactId>
<excluded>true</excluded>
</webModule>
</modules>
</configuration>
</plugin>
</plugins>
</build>