To get it to work, I applied the following changes based on the same scripts in v1.4.5 and suggested by Shanker in an earlier post. Can you please advise what the actual fix is?

/etc/rc.d/init.d/tomcat6
#Get instance specific config file
if -r "/etc/sysconfig/${NAME}" ; then
. /etc/sysconfig/${NAME}
#export TOMCAT_CFG=/etc/sysconfig/${NAME} # <--- COMMENTED THIS LINE
fi

/usr/sbin/dtomcat6
UNCOMMENTED THE BELOW SECTION:
#Get the tomcat config (use this for environment specific settings)
if -z "${TOMCAT_CFG}" ; then
TOMCAT_CFG="/etc/tomcat6/tomcat6.conf"
fi

if -r "$TOMCAT_CFG" ; then
. $TOMCAT_CFG
fi

The issue has been analysed and it is found that tomcat 6.0.36 version had changed the dtomcat6 script in a way that it does not set the CATALINA_BASE and CATALINA_HOME environmental varilables.

In CPBM case, tomcat supposed to have read the /usr/share/cloud/portal/tomcat6.conf file and set the environmental variables accordingly.

In tomcat 6.0.36 version, the following lines are commented:
#if [ -r "$TOMCAT_CFG" ]; then
# . $TOMCAT_CFG
#fi

To get CPBM started, it is sufficient to uncomment the above three lines.

then, remove the /var/run/cloud-portal.pid file
rm /var/run/cloud-portal.pid

then, start the cloud-portal
service cloud-portal start