Vringo Inc., a company that specializes in suing companies for patent infringement, on Thursday said it had agreed to buy a collection of patents on wireless network technology from Nokia Corp. for $22 million in cash.

New York-based Vringo is buying more than 500 patents and patent applications, including 109 U.S. patents. Vringo said Nokia, the Finnish maker of cellphones, would share in some of the revenue generated by asserting the patent portfolio.

Vringo issued 9.6 million shares to raise the money for Nokia, and its stock fell 11 cents, or 3.3 percent, to $3.33 in afternoon trading.

For a company like Nokia, selling patents to a company that litigates but doesn’t make wireless equipment can be a winning proposition. If Nokia were to sue other equipment makers for patent infringement, they could countersue Nokia for infringing on their own patents. Since it doesn’t have any applicable products, a company like Vringo can’t be countersued for patent infringement.

Apart from its patent business, Vringo sells what it calls video ringtones for phones.

One of the members of Vringo’s litigation team is Donald Stout, the co-founder of NTP, which in 2006 wrested a $612.5 million settlement from Research In Motion Ltd., the maker of the BlackBerry. Another member is David Cohen, the former senior litigation counsel at Nokia.

Vringo is suing Google over how it links ads to searches. That suit goes to trial in October.

Last year, Nokia and Microsoft Corp. handed over 2,000 patents to Mosaid Corp., a Canadian patent licensing company and maker of memory chips, in exchange for a share of licensing and litigation revenue.