Even though they said it wasn’t required of them, Yahoo (NSDQ: YHOO) and Google are waiting 3.5 months before implementing their agreement, just to avoid any antitrust problems. So, will there be any problems? UBS analyst Ben Schachter hosted a call (closed to the press, unfortunately) on the matter yesterday with attorney Glenn Manishin of Duane Morris LLP. The key takeaway, from a summary report: It’s all about defining the market, which is often the case in situations like this (see: XM-Sirius). Is the market just search advertising? Or is it the broader world of online advertising? Or perhaps it should be the whole advertising industry. This is what regulators will chew over, and each of those possibilities gets progressively better for Yahoo-Google (NSDQ: GOOG).

If the market is defined as just search advertising that’s obviously the worst, and the deal could face stiff resistance. Google might already have monopoly-like market share even before this deal comes to fruition. If the market is defined more broadly as online advertising, then they should be okay. And if we’re talking the whole ad industry, that’s obviously the best. All in all, it doesn’t sound as though Manishin is particularly concerned that the deal will get held up.

-- So why the wait? If it wasn’t necessary, and the deal isn’t likely to trigger any alarms, why are they waiting 3.5 months? Manishin doesn’t see it as a bad omen. Basically, if they went ahead, and regulators wanted to look into it, the government would have to file a court injunction, and that’s when things start to look bad. Better to just take the time now and get it right with no hitches along the way. As for Microsoft’s (NSDQ: MSFT) inevitable attempts to block it, if it’s seen as self-serving, then they’ll have little effect, proving, basically, that there are competitors (just as the terrestrial broadcasters demonstrated that XM-Sirius had competition by complaining loudly). But, given Microsoft’s success at delaying Google-DoubleClick, the company does know how to stall a deal.

• Updated: Icahn: Yahoo’s Google Deal ‘Might Have Merit’, ‘May Be Better Than Microsoft’
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