Beleaguered Internet firm Yahoo! has sued social networking major Facebook, alleging violations of as many as ten patents including those related to online advertising and personal privacy.

Marking the escalation of patent disputes in the fast growing social media sector, Yahoo!'s salvo comes at a time when Facebook is preparing for a mammoth initial share sale.

Legal fights over alleged patent infringements are common in the technology space as reflected in the instances involving giants such as Apple, Samsung, HTC, Motorola and Microsoft.

Asserting that the patents relate to "cutting edge innovations", Yahoo! in the lawsuit has even claimed that Facebook's entire social networking model is based on its technology.

"Facebook's entire social network model, which allows users to create profiles for and connect with, among other things, persons and businesses, is based on Yahoo!'s patented social networking technology," according to the lawsuit filed with a Federal Court in California yesterday.

Yahoo!'s lawsuit also comes close on the heels of Scott Thompson taking over the reins of the Internet entity, grappling with severe competition from Facebook and many other online players.

"For much of the technology upon which Facebook is based, Yahoo! got there first and was therefore granted patents by the US Patent Office to protect those innovations," the lawsuit noted.

The Internet firm has pointed out that the patents relate to cutting edge innovations in online products including messaging, news feed generation, social commenting, advertising display and privacy controls.

These innovations dramatically improve user experience, privacy and security and enhance the ability of advertisers to connect with users, it added.

"Yahoo! is harmed by Facebook's use of Yahoo!'s patented technologies in a way that cannot be compensated for by payment of a royalty alone.

"Facebook's use of Yahoo!'s patented technologies has increased Facebook's revenue and market share because it does not have to recover the costs of time involved in the development of the technology," the lawsuit said.