As Microsoft and Yahoo await government approval of their pending deal to join their two search businesses at the hip, the two companies received an important endorsement today from the world’s top advertisers.

In a letter today from the American Association of Advertising Agencies, and signed by the CEOs of the Publicis Groupe, WPP, Interpublic, and Omnicom, the advertisers gave their full support to the deal, urging “the Department of Justice to bring its antitrust review to a speedy conclusion.” The letter notes that the deal would strengthen Microsoft’s and Yahoo’s search advertising offerings, and thus would be good for competition.

Advertising agencies are wary of being beholden to an evermore powerful Google, and thus want to foster alternatives which might act as a counterweight. Most industry watchers expect the deal to pass DOJ scrutiny.

Below is a copy of the letter sent by the AAAA:

AMERICAN ASSOCIATION of ADVERTISING AGENCIES

Nancy Hill
President
Chief Executive Officer

October 19, 2009

Advertising is the fuel that powers the Internet. Most websites depend on online advertising to survive – it’s what allows them to offer consumers free content and services.

A very important form of online advertising is search advertising – the sponsored links that appear when a search engine answers a query. A healthy, competitive market for search and search advertising is crucial to the Internet’s future.

We believe that Yahoo! and Microsoft’s proposal to combine their technologies and search platforms is good for advertisers, marketing services agencies, website publishers and consumers.

These benefits are too important to wait for. As leading members of the advertising and marketing services industry, we urge the Department of Justice to bring its antitrust review to a speedy conclusion. This proposal enhances competition, and should be allowed to take effect as soon as possible.

Sincerely,
Nancy Hill,
President & CEO

Maurice Levy,
Chairman and CEO, Publicis Groupe

Michael I. Roth,
Chairman and CEO, Interpublic Group of Companies

Martin Sorrell,
CEO, WPP
John Wren,
President & CEO, Omnicom Group