firefox-bin: error while loading shared libraries

I'm trying to use old 32-bit firefox (v 3.6) on 64-bit CentOS machine (CentOS 6.4) and getting the following error:
/usr/local/firefox/firefox-bin: error while loading shared libraries: libXt.so.6: cannot open shared object file: No such file or directory 

Firefox won't start because of missed library libXt.so.6. I've googled a lot, but seems like no solution exists suitable for me. So I have ho figure it out by myself.

Let's start:

- Check for missed libraries: firefox lists missed library in the error text, i.e. :
# firefox --version
/usr/local/firefox/firefox-bin: error while loading shared libraries: libXt.so.6: cannot open shared object file: No such file or directory

- Check if library is present in the system (notice that for x86_64 systems there are two library folders: /usr/lib and /usr/lib64):
# locate libXt.so.6
/usr/lib64/libXt.so.6
/usr/lib64/libXt.so.6.0.0
Probably missed 32-bit version of library, so we need to find where it is and install

- Find which package provides library needed (using 'yum whatprovides */libraryname' command)
# yum whatprovides */libXt.so.6
libXt-1.0.2-3.2.el5.i386 : X.Org X11 libXt runtime library
Check careful (in case of 32 and 64 bit versions you should find the appropriate one)!

- Install needed package:
# yum install libXt-1.0.2-3.2.el5.i386

- Rebuild locate db and check of files exist now:
# updatedb
# locate libXt.so.6
/usr/lib/libXt.so.6
/usr/lib/libXt.so.6.0.0
/usr/lib64/libXt.so.6
/usr/lib64/libXt.so.6.0.0

Missed 32-bit versions are available now