• by David Goetzl , February 11, 2008

Nearly 33% of all online videos watched in the U.S. in December took place via a Google-owned site. And a combined Microsoft-Yahoo would have accounted for only 5%, according to new figures from comScore.

In total, Americans viewed more than 10 billion videos online in December, the most for a single month since comScore began tracking the data in January 2007. Of the 3.3 billion viewed on Google properties, more than 97% took place via YouTube.

A combined Microsoft-Yahoo entity would have accounted for 521 million--good enough to vault past Fox Interactive Media into a strong second place, but still well below the expanding Google. Microsoft alone did account for more than the AOL-led Time Warner network.

Fox Interactive had 358 million videos viewed in the month--93% via MySpace, a site that has looked to bulk up its TV offering (including streaming Super Bowl spots last week.)

Overall, some 141 million Americans viewed videos online in December.

Yahoo's sites came in third with 340 million videos viewed, followed by Viacom's with 238 million. Viacom's MTV Networks has sought to drive more traffic to its portfolio of sites to keep up with the changing interests of its younger audience.

Microsoft's sites came in fifth with 180 million, giving the Microsoft-Yahoo combo some 521 million. Microsoft has launched a bid to take over Yahoo to mount a stiffer challenge to Google.

Time Warner, which owns AOL, saw its sites finish sixth with 174 million streams.

ABC.com, the first network Web site to offer full episodes of hit shows, posted 47 million streams in the month, good for 10th place. ESPN topped it with 84 million--a figure that may have been boosted by the addition of hundreds of live events, including NBA basketball games, on its ESPN 360 offering.

Also in December, Google had the most unique viewers, according to comScore, with some 79 million. Microsoft-Yahoo would have accounted for 58 million. FIM was second, however, with 44 million, while the AOL/Time Warner entity was fourth with 27 million.