Convert Excel to CSV

[Tim Wunder]

I'm trying to find a command line utility that will convert an Excel 
file to a .csv text file.

I've found catdoc & xls2csv at 
http://www.45.free.net/~vitus/ice/catdoc/, which looks like it should do 
the trick. I've downloaded, compiled and installed it. Unfortunately, 
when I try to execute
$ xls2csv -x FileName.xls
I get this error:
FileName.xls is not OLE file or Error

Any ideas? Any recommendations for a different utility that would 
perform the conversion?

Thanks,
Tim