Websphere 6.1 and above comes with in-built portlet container. Websphere load portlet api with all web application. There is no settings in adminstraive console to disable portlet container, it is an over-ahead on memory. This specifically make an problem or java based portal server e.g jetspeed-2 , Liferay etc. There is only one way to disable it. You add the following context param to disable portlet container for your web application. This also saves the memory foot print.
<context-param>
<param-name>com.ibm.websphere.portletcontainer.PortletDeploymentEnabled</param-name>
<param-value>false</param-value>
</context-param>
