Remarks: Note the following procedure seemed to corrupt dependencies for my kernel to a point where it was easier to reinstall the OS than remove conflicting packages and install correct ones. 

Add a new repository to apt sources:

Create a new file in sources.list.d

kdesudo kate /etc/apt/sources.list.d/libre-office.list

Add this line:

deb http://backports.debian.org/debian-backports squeeze-backports main

Running command:

[[email protected] c]$ sudo apt-get install libreoffice

 

Reading package lists… Done
Building dependency tree
Reading state information… Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
libreoffice : Depends: libreoffice-core (= 1:3.5.4+dfsg-3~bpo60+2) but it is not going to be installed
Depends: libreoffice-writer but it is not going to be installed
Depends: libreoffice-calc but it is not going to be installed
Depends: libreoffice-impress but it is not going to be installed
Depends: libreoffice-draw but it is not going to be installed
Depends: libreoffice-math but it is not going to be installed
Depends: libreoffice-base but it is not going to be installed
Depends: libreoffice-report-builder-bin but it is not going to be installed
Depends: libreoffice-filter-mobiledev but it is not going to be installed
Depends: libreoffice-java-common (>= 1:3.5.4+dfsg~) but it is not going to be installed
E: Broken packages

 

The dependency problems seemed difficult to fix, so I tried:

[[email protected] c]$ sudo aptitude -t squeeze-backports install libreoffice