Yess you can partition the hard drive so one side is formatted for mac and the other for PC.
There are a coulpe of other ways to do it to,
some options are, you can get software on your mac to read your PC formatted hard drive, and vice versa
The other opetion is to use disk utilities to and partition your hard drive. This will clear your hard drive so you will need to make sure all of your files as backed up first
mac side as:Mac OS extended (journaled)
PC side as: MS-DOS
This website should guide you through some of the options
Many thanks for your response. My Mac can read the PC files, but I cannot save from the Mac to the hard drive as it is formatted NTFS. I was hoping I could partition the disk and only reformat the unused portion as fat32 so the Mac can save to that portion. If I understand correctly I must reformat the entire drive and will be able to reformat part as fat 32 and part as NTFS, but that I will lose the data currently on the drive in this process. I was hoping to reformat part of the disc as fat32 without losing the data currently on the disk, this seem not possible.
Sorry as far as i know when you partition a hard drive using dirk utilities it will completely format the drive so you will loose all files unless they are backed up.
If you can back up the work then mabe the nest option is to use something like "paragon NTFS" which will allow you to read and right files onto your hard drive but keeping the original formatting.
Also fat32 is only compatibles upto 2TB and maximum file size is 4Gb so setting the entire hard drive to that would not be ideal either...
If you want to be able to open and save files from a NTFS formatted drive, just spend the $20 on Paragon's NTFS for Mac.
No need to worry about reformatting, etc. A good investment for sharing a drive with Windows and OS X.