LIBTOOL Issue

Hi.

I am facing the following error.
Makefile.am:23: error: Libtool library used but 'LIBTOOL' is undefined
Makefile.am:23: The usual way to define 'LIBTOOL' is to add 'LT_INIT'
Makefile.am:23: to 'configure.ac' and run 'aclocal' and 'autoconf' again.
Makefile.am:23: If 'LT_INIT' is in 'configure.ac', make sure
Makefile.am:23: its definition is in aclocal's search path.

This is getting generated when the ./bootstrap runs while executing build.sh. Question is i already have the libtool installed on my end. Why am i running into this issue if i already have the tool. Also another question what version of pkgconfig is required by the tool installation ?

P.S : I use CentOS for all the activities.

Thanks,
Shravan.