• by Mark Walsh , May 4, 2011

Facebook accounted for nearly a third (31.2%) of U.S. display ad impressions in the first quarter, nearly double the 16.2% from the year-earlier period and up from 26% in the fourth quarter, according to the latest data from comScore.

The 346 billion display ads Facebook served in he quarter was more than triple its nearest rival, Yahoo, which generated 112 billion impressions, or 10.1% of the total. Microsoft ranked third, with 4.8% of impressions, followed by AOL, 3%, and Google, with 2.5%. There were 1.1 trillion ads served overall in the quarter.

AT&T ranked as top advertisers, generating 19.5 billion impressions, or 1.8% of display ads. The telecom giant was followed by Experian Interactive, with 1.5%, Scottrade and Intuit, each 1%, and Verizon, 0.9%. Daily deals powerhouse Groupon accounted for 0.7% of display ads. Among other findings:

-In terms of display ad spending, AT&T was also tops, with a 2.1% share. Rounding out the top five were Scottrade (1.9%), Toyota (1.2%), and Netflix (1.1%).

-The top consumer goods advertisers ranked by display ad spending were: Procter & Gamble, Mars, Kellogg's, General Mills and Kraft Foods.

- 95 different advertisers delivered at least 1 billion display ad impressions and 293 advertisers spent at least $1 million on display ads during the quarter.