Libreoffice 4.4 --headless issue on Centos 6.6

When converting a .docx to a PDF using the --headless, --invisible, and both flags at the same time, I got the following:

Failed to open display

/opt/libreoffice4.4/program/soffice.bin: error while loading shared libraries: libGL.so.1: cannot open shared object file: No such file or directory

When I was using Libreoffice 4.0.4.2 the command worked without any problems and I am unsure of what I am doing wrong. I should also note that this is a server install, there is no graphics display.

(This is 64 Bit)

I succeed to use 4.4 on my Centos 6.6 (64 bits) without GUI by installing mesa-libGL mesa-libGLU .

yum install mesa-libGL mesa-libGLU

I am very happy because I needed this version and not 4.1 .