As reported earlier today on SearchEngineLand.com, Microsoft seems to have inadvertently tipped its plan to rename Microsoft Advertising to the "Yahoo Bing Network" and to rebrand its own online ads as "Bing Ads."

Update (September 10): Microsoft officials sent overnight the following clarification:" Microsoft Advertising is not changing branding. What was called the 'Search Alliance' is now the Yahoo Bing Network. AdCenter is being rebranded to Bing Ads." (AdCenter is Microsoft's search-based advertising tool.)

When I checked around 7 p.m. PT on September 9, Microsoft was displaying posts, a new Twitter account and a Facebook page showing the new branding.

Yahoo Bing Network looks to be the new name for the combined Yahoo and Microsoft core search sites, which Microsoft is touting as accounting for 30 percent search share in the U.S. Microsoft (and Yahoo) also are highlighting as part of the rebranding that it's not just Yahoo that is powered by Bing. On the new Facebook page for the rebranded advertising network, the pair emphasized that the "Yahoo Bing Network is the combined search advertising marketplace made up of Yahoo, Bing, and partner sites," like Facebook, Amazon, Monster, WebMD, CNBC, and Viacom, plus networks like The Wall Street Journal Digital Network.

"The robust Yahoo Bing Network reaches 151 million searchers in the U.S. who are likely to spend 124 percent more than the average searcher, and likely to spend 5 percent more than Google searchers in the U.S. That also means you can reach 46 million unique searchers in the U.S. who aren't using Google, claimed Microsoft on the new Yahoo Bing Network About page. "A similar result holds true worldwide, with 489 million unique searchers, 92 million of whom do not use Google; and worldwide the Yahoo Bing Network represents an audience who is likely to spend 124 percent more than the average searcher and 78 percent more than Google searchers worldwide."

Since Marissa Meyer took over as CEO of Yahoo earlier this summer, there has been quite a bit of speculation about whether Yahoo would continue to put its search eggs in Microsoft's basket, as the partnership between the two hasn't worked out financially for Yahoo. As Search Engine Lang noted, it's interesting that Yahoo gets top billing in the rebranded Microsoft Advertising name.

Microsoft hired Mark Penn, a Washington pollster and strategist, in July, with one of his first charges being to work on growing Bing's share.

Last week, Microsoft announced a new ad campaign -- "Bing It On" -- aimed at showing consumers that Microsoft has improved the relevancy of its Bing search results to the point where they meet and/or beat those generated by Google. When I asked one Microsoft exec last week why Microsoft is continuing to plug away at gaining search share vis-a-vis Google, he noted that increasing search share is key to improving Microsoft's online advertising position and relevancy.

Microsoft also forged a deal via which Bing will be the default search engine on the new Amazon Kindle Fire HD tablets announced last week, Microsoft officials acknowledged.

I asked Microsoft officials for comment on the company's rebranding plans beyond the information that is now available online. No word back so far.

This article originally appeared on ZDNet.