In 2012, a big clash between Google, the world's largest Internet search engine, and Facebook, world's No.1 social network service, is being predicted.

Forbes reported analysts as saying that year 2012 would be a critical year for both the companies. Last June, Google issued a challenge to Facebook by launching its own social network called Google+ (Google Plus). But Facebook counterattacked.

Facebook has posed serious problems for Google, most notably by walling off the social network’s content from Google’s search engine, Baird's equity research analysts said.

The problem for Google is that its business model relies on its ability to index the Web. Thus, when Facebook walls off its site, it’s essentially blocking a significant, and growing, portion of the Web. Google's index has been faced with an ever-increasing blind spot for search, pointed out the analysts.

To solve this, Google has launched its own ambitious social network called Google+. And though it has not yet become a threat to Facebook, yet, soon, it could grow powerful as Google+ has the backing of Google, which has a powerful influence over the Web and is sitting on a massive cash pile.

This fierce battle will decide who will monopolize online advertisement revenue. And it seems that the impact of the clash will be felt over the next 10 years.

This is a fight for survival for Facebook -- and for relevancy for Google. What happens in 2012, will make the difference between whether there is a Facebook by the end of the decade and whether Google can become truly relevant outside of search, senior technology analyst Rob Enderle told ComputerWorld.

And, analysts have different opinions about who the winner will be.

According to some analysts, Google will win. First of all, no one can deny that the Internet world currently belongs to Google. With Google controlling more than 65 percent of U.S. search advertisement -- against Yahoo's 16 and Microsoft's Bing 14 -- and more than 50 percent of the global market, it cannot be denied that Google has captured the market. And, Google's Android OS is set to make synergy as it will be integrated into Google+, luring people to live in a Google world.

But Facebook poses a threat to Google. Facebook boasts 750 million users, of whom half log in every day. Accordingly, it causes damage to Google's functions such as Gmail and Gchat. Furthermore, Facebook is also reportedly working on its own search engine. Indeed Facebook threatens the online dominance of Google. And once Facebook launches the initial public offering expected in the first half of 2012, it will not face any cash shortage when it battles with Google head on.

Indeed, year 2012 would see a full-scale battle between Google and Facebook and it is too early to say that who the ultimate winner will be.