Thanks Jeremy for your continued help. I am pasting the stack trace here.
Application is using the properietry framework to loolup the ejb. The jndi name that I specified was "mainservlet/ejb/tpaServices_com_ing_tpa_services_ApplicationServiceHome"
I have also used all the below combinations.
"ejb/tpaServices_com_ing_tpa_services_ApplicationServiceHome"
"java:comp/env/ejb/tpaServices_com_ing_tpa_services_ApplicationServiceHome"
"java:comp/env/mainservlet/ejb/tpaServices_com_ing_tpa_services_ApplicationServiceHome"
Nothing worked till now.