-By John Consoli, Mediaweek

NEW YORK The presidential campaign of Republican candidate John McCain, not wanting to be outdone by rival Democratic candidate Barack Obama, has made a $6 million advertising buy on NBC Universal's Olympic Games coverage which begins this Friday night.

The McCain campaign buy comes several weeks after the Obama campaign made a $5 million ad buy. McMain's move was not unexpected.

Sources familiar with the ad buys of both candidates said that the Obama ad buy was made several weeks ago, but details of the ad buy only became public last week. The McCain ad buy was made in recent days and became public today.

NBC had no comment on the ad buys of either candidate, although a listing of the ad buys can be found in NBC Universal's Political File, which must record all ad dollars spent by political candidates.

Ad buys for both candidates include on-air spots on the NBC broadcast network and NBCU cable properties over the course of the 17 days of Olympic Games coverage. Candidates' spots will run in prime time, late night and on weekend daytime coverage of the event.