The battle for Yahoo is heating up.

When Jack Ma, chairman of Chinese e-commerce company Alibaba Group, announced last month that he wanted to buy Yahoo! — which itself owns 40 percent of Alibaba — he touched off a frenzy of tire-kicking by entities ranging from private equity firms to Microsoft. Media outlets including the New York Times and the Wall Street Journal have cited unnamed sources who say Microsoft is in talks with a consortium of investors including private equity firm Silver Lake Partners, but it's not the only tech giant eyeing Yahoo. Microsoft's archrival Google also is reported by those same publications to be exploring strategic options, although the word at this point is unofficial and informal.

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Google doesn't actually want Yahoo, says Scott Kessler, Internet equity analyst at S&P Capital IQ. The company just doesn't want Microsoft, with its rival Bing search engine, to get its hands on any Yahoo assets that could threaten Google's search dominance.

"The fact that you have a player potentially like Microsoft means that Google at least needs to get involved at some level, if for no other reasons to know what's going on," he says. "Google is inclined to get involved because they're concerned about Microsoft having a place in this process and potentially having a lot to say about Yahoo's future."

Reports of Google's interest could be a strategic advantage for Yahoo, since it would likely drive up the eventual price. Of course, Google wouldn't mind driving up the price for any acquisition Microsoft might make.

Even if Google wanted to acquire any part of Yahoo outright, such a deal would be unlikely to pass muster with antitrust regulators, analysts say. Google and Yahoo tried to form an advertising partnership in 2008 and abandoned the effort after getting strong signals that the Department of Justice would work to block the deal. Regulators would be more likely to look favorably on a Yahoo-Microsoft partnership, which is what worries Google — another reason for the company to get involved.

While Yahoo's content and user base might be an attractive addition to Google, which previously acquired YouTube, Kessler thinks it's unlikely that Google would try to buy Yahoo assets like Flickr on a piecemeal basis. Google's end game would be monetization of the user traffic via advertising sales, so a takeover of any part of Yahoo's core business would run into the same antitrust objections Google has experienced before, he said.

If Google does have a genuine interest in Yahoo, it has a couple of options. Google might view Yahoo's Alibaba connection as a way into the Asian market. "I could see a scenario where Google is maybe more interested in some of the other assets like the international investments in Japan and China," Kessler says. Despite a years-long, often politically fraught effort, Google has failed to establish much of a presence in China, so this could be an opportunity to grow there.

Ironically, Google does have a business interest in keeping Yahoo healthy. Like the Joker to Google's Batman, having a slightly less powerful rival establishes a kind of equilibrium. Kessler points out that when Apple was on the ropes shortly after reinstating Steve Jobs in what was viewed at the time as a last-ditch effort to turn the company around, Microsoft made a substantial investment in its smaller rival. Without Yahoo, Google would face even greater legal challenges to its market dominance.