Create partition on master boot record external drive?

[igneousc]

I have an external hard drive with a few hundred GB on it, but it has around 2.5 TB free. I want to create a partition so I can run time machine on the drive. The current partition is ExFAT, and when I go into disk utility it wont let me add a partition because it uses the master boot record partition scheme. Is there any way to add a partition without wiping the drive? I couldn't find any answers for this, but I'd prefer to find a free program to use if possible since it seems that disk utility can't do this.
thanks

 

[prisstratton]

I have an external hard drive with a few hundred GB on it, but it has around 2.5 TB free. I want to create a partition so I can run time machine on the drive. The current partition is ExFAT, and when I go into disk utility it wont let me add a partition because it uses the master boot record partition scheme. Is there any way to add a partition without wiping the drive? I couldn't find any answers for this, but I'd prefer to find a free program to use if possible since it seems that disk utility can't do this.
thanks

Time Machine requires a GUID or Apple Partition Map (not MBR).