AT&T released its full-year 2009 earnings today, and its Advertising Solutions unit, which includes print Yellow Pages and Yellowpages.com, posted total revenues of US$4.8 billion, a 12.6 percent decline.

AT&T online directories unit Yellowpages.com grew 12.7 percent in Q4, compared with Q3 growth of 20.7 percent. Total online revenues for the year were US$884 million, which accounts for about 18 percent of total Advertising Solutions revenues. This puts AT&T at the high end of North American publishers in terms of share of revenues from online.

Margins took a hit in 2009, not a surprise given the grim economic environment. BIA/Kelsey calculates the Advertising Solutions 2009 margin at 39.2 percent, compared with 45.5 percent in 2008.

One avenue that AT&T will pursue this year to shore up its position online — increasingly critical to restoring the business to growth — is the launch of social media site Buzz.com, currently in invitation-only “alpha” phase.

This article from Forbes yesterday outlines the new product — widely reported to be in the works for some time. Yellowpages.com President David Krantz is interviewed in the piece. While the site draws immediate comparisons to newly flush Yelp, there are some key differences, notably the choice of a “favorites” option over the use of full user-generated reviews.

Buzz.com will be a critical test case for how traditional directory publishers (a label AT&T Ad Solutions no doubt will increasingly resist) can pivot their approach to business into social media. Other directory publishers actively involved in social media include Eniro, European Directories and Truvo.