Why do kickstart files not find rpms contained in additional repositories during installation of Red Hat Enterprise Linux 7.1?

Issue

• A Kickstart installation of Red Hat Enterprise Linux 7.1 fails to find the RPMs defined in the following repository

repo --name="Broadcom Driver NetXtreme II + Test Agent" --baseurl=http://www.example.com/additionalrepo/

• After excluding the rpms from above repository, installation works as expected.
• The same rpm can be installed once installation is completed and a .repo file is created in /etc/yum.repos.d/ directory.