The top 100 B2B advertisers spent an estimated $6.05 billion on B2B advertising last year, down 1.9 percent from $6.17 billion in 2006, according to a BtoB Magazine analysis of ad spending from TNS Media Intelligence, MarketingCharts writes.

Total B2B ad spending was $12.95 billion last year, down 2.9 percent from $13.35 billion in 2006, according to the data, which include estimated B2B spending on business magazines, consumer magazines, newspapers, TV, radio, online and outdoor.

Leading the '07 list of Top 10 spenders were telecommunications companies, particularly those marketing wireless and data services to mobile business professionals:

• Verizon Communications was the top B2B advertiser in 2007, spending an estimated $407.9 million, up 10.4 percent over 2006.
• Last year's No. 1 spender, AT&T, fell to No. 2, spending $364.1 million, down 12.9 percent from 2006.
• Sprint Nextel rounded out the top 3, spending $283.5 million on B2B ads, down 2.3 percent from 2006.

Among the top 10 B2B advertisers of 2007, all but Citigroup had made the top 10 list for 2006, BtoB reports. Citigroup moved up 13 spots, from No. 20 to No. 7, spending nearly 76 percent more than in 2006.

Other findings from BtoB's analysis, below.

Online Advertising

• B2B internet display ad spending in '07 was relatively flat, declining 0.4 percent from 2006.
• The Top 10 B2B online advertisers were led by Monster Worldwide, followed by Hewlett-Packard and job site Dice.com. All three decreased their ad spend from the previous year.

• Meanwhile, others in the top 10 significantly increased their online ad budgets, including No. 4 Microsoft, No. 5 Verizon and No. 8 IBM Corp.

Media Categories

• B2B advertisers spent nearly a quarter (24.3 percent) of their ad budgets on business publications, and nearly half as much (12.5 percent) on consumer magazines.
• Network TV, at 11.2 percent, was the third-highest recipient of B2B ad dollars, followed by Internet (display only) and Newspapers with 10.9 percent each.
• Cable TV (8.5 percent), spot TV (5.2 percent), national newspapers (4.0 percent), local radio (3.8 percent) and outdoor (3.4 percent), followed.

For a full listing of the Top 100 B2B Advertisers, including ad spending by medium, as well as the top 50 B2B Online Advertisers, see this document (pdf) from BtoB.