The patent-related legal scuffle between smartphone market arch-rivals Apple and Nokia took an interesting turn on Friday, when Apple - sued by Nokia in October for allegedly infringing on ten of its patents - counter-accused Nokia of patent infringement as well as anti-competitive practices.

Nokia had said in its lawsuit filing that Apple was apparently trying to get a "free ride" off of its intellectual property, infringing on as many as ten patents pertaining to an array of mobile data technologies, including speed encoding and decoding, security and encryption.

However, Apple has now accused the Finnish phone maker of infringing on 13 of its patents. Giving a pointed response to Nokia's patent-infringement allegations, Apple General Counsel Bruce Sewell said in a statement: "Other companies must compete with us by inventing their own technologies, not just by stealing ours."

Furthermore, Apple also accused Nokia of being involved in competition-thwarting behavior, and added that Nokia failed to live up to its commitments about licensing its own technology at fair and reasonable terms.

With the Nokia and Apple brawl intensifying after Apple's counter-suit against Nokia, analysts opine that the legal dispute could potentially involve hundreds of millions of dollars in annual royalties; and that it might take the two companies years to settle their patent-linked differences and eventually come to a licensing agreement.