When setting up the Android ADT on CentOS 6.3 64-bit (x86_64), it is necessary to include 32-bit libraries. The following command line will ensure the proper libraries are available. The 64-bit libraries are included on the command line even though they will already be installed on the OS.
# yum install glibc.x86_64 glibc.i686 libstdc++.x86_64 libstdc++.i686 ncurses-libs.x86_64 ncurses-libs.i686 zlib.x86_64 zlib.i686