Nope.

http://www.microstockgroup.com/general-stock-video/who-can-help-me-with-keywording-of-videos/

I use a spreadsheet with a master copy of the metadata, and I use sheet cell references to copy the data to separate sheets for each agency.

if a cell A2 needs to be copied, you reference it like so: sheet_name!A2

then I save each sheet for each agency.

for some agencies, I save a sheet and run it through a script that makes changes unique for that agency.