Google Inc. (GOOG) is increasingly pushing into the markets for mobile phone software and computer operating systems, areas where Apple Inc. (AAPL) has strongholds. Because the business models of the Internet giant and the hardware maker are so different, however, a head-on clash is unlikely anytime soon.

The latest round of rumors suggesting the two tech giants are girding to compete came Thursday as speculation mounted Apple had purchased online mapping start-up Placebase Inc. to free itself from Google's mapping technology, which now comes with Apple's popular iPhone.

The speculation over a possible Placebase deal stemmed from Apple's apparent hiring of two top executives from the small Los Angeles mapping software company. That provoked a host of blog posts suggesting the once-cozy relationship between the two partners appears to be cooling.

That might be jumping the gun. While Google's new Android cellphone operating system is starting to gain traction and it plans to release its Chrome computer operating system soon - both of which could challenge Apple products - Wall Street analysts quickly point out the Mountain View, Calif. search giant doesn't participate in one of Apple's core markets: hardware.

"I don't really view Google and Apple as competitors," said Kaufman Brothers analyst Shaw Wu. "I really don't see that changing a lot in the next couple years."

Google declined to comment. Apple was not immediately available for comment.

The chummy relationship between Google and Apple appeared to deteriorate in July when Apple said it had turned down the Google Voice iPhone application in its current form because it seemed to alter the iPhone's core functions and interface. Apple's decision prompted a request for information from the U.S. Federal Communications Commission.

Late last month, Google raised some eyebrows when it said Apple had "rejected" Google Voice, contradicting Apple's contention that it was still studying Google's application.

Meanwhile, Google Chief Executive Eric Schmidt resigned from Apple's board in August amid growing regulatory scrutiny over deep ties between the boards of the two companies. Apple CEO Steve Jobs said the mutual decision to step down made sense as Google entered more of Apple's core businesses.

"Eric's effectiveness as an Apple board member will be significantly diminished, since he will have to recuse himself from even larger portions of our meetings due to potential conflicts of interest," said Jobs in a statement.

Despite the cooling relationship, Wall Street analysts say the two companies are still so different they are unlikely to get in each other's way soon.

Google counts on search advertising for about 97% of its revenue and many analysts say that figure is not expected to significantly shift soon. Apple, in contrast, gets about 82% of its revenue from the sale of computer hardware, iPod music players and iPhones, as well as related products and services.

"By and large, their businesses don't overlap and are quite complementary," said Andy Miedler, analyst at Edward Jones.

Piper Jaffray analyst Gene Munster says Google's Android is a minor issue between the companies at this point, even though many bloggers point to mobile phones as a potential turf battle.

He also notes that while Schmidt may have left Apple's board, the Google CEO turned up when Jobs recently unveiled the company's latest lineup of iPods.

"If things were truly getting more abrasive between the two, why was Schmidt at the Apple event?" he asked.

He also argues that Google has little to lose even if it steps on Apple's toes because Apple doesn't have much choice but to keep using Google as the default search engine for its Safari Web browser, as well as on its iPhone.

Google shares closed down 1.7% Thursday at $487.20, while Apple shares closed down 2.4% at $180.86 on a down day for the market.

-By Scott Morrison; Dow Jones Newswires; 415-765-6118; scott.morrison@dowjones.com; and Ben Charny, 415-765-8230; ben.charny@dowjones.com