• by Joe Mandese  @mp_joemandese, June 9, 2011

In a key financial milestone, the Interpublic Group Wednesday achieved an "investment grade" ranking from credit ratings service Moody's, meaning the publicly traded agency holding company is deemed highly bankable in the financial marketplace. The move marks the culmination of a long, and hard fought turnaround process for the parent of media shops like Initiative, Universal McCann, Reprise Media, Geomentum, Shopper Sciences, and full-service shops like McCann WorldGroup, Lowe and DraftFCB.

"[Interpublic] is now an investment grade credit, according to two of the three agencies (Fitch upgraded in October 2010)," Deutsche Bank analyst Matt Chesler wrote in an investor recommendation released early this morning. He noted that Interpublic, "is significantly improved from a competitiveness and liquidity standpoint heading into any moderation/slowdown -- a dramatically better risk profile."

While the upgrade mainly affects the confidence of lending institutions to bank with and give credit to the agency holding company, it likely will also influence the underlying confidence of investors to buy or hold Interpublic stock, and will enable Interpublic to borrow money more cheaply to fund operations and potential acquisitions.

When it comes to acquisitions, Interpublic has been one of the more tepid of Madison Avenue's big agency holding companies, virtually sitting on the sidelines as bigger brethren - especially Publicis and WPP - gobbled up important strategic assets, particularly digital marketing services shops.

Among Interpublic's bigger deals were the acquisition of search specialty shop Reprise Media a few years ago, and the acquisition of a majority stake in DUMBO digital shop Huge last year.

Noting that Moody's improved Interpublic's credit rating "two notches" despite the "foggy" macro-economic picture that Madison Avenue is operating in, Deutshe's Chesler commented that it, "says much about [Interpublic's] improved credit profile."

.