Blackberry sues Nokia in patent clash
Blackberry is suing Nokia over claims that the Finnish company has made use of nearly a dozen of its inventions without permission.
The patent infringement allegations concern data transmission technologies involved in 4G and other types of mobile networks.
The Canadian firm claims several of Nokia's transmitters and software programs use its intellectual property.
Nokia told the BBC that it was looking into the matter.
"We're aware of the complaint, will study the claims made and take whatever steps are necessary to defend our rights," said a spokeswoman.
The case is being pursued in the US.
Blackberry is seeking payment, rather than trying to block Nokia's use of the 11 patents, according to court documents published by the news site Ars Technica.
The filings include claims that Nokia was aware of the patents' existence as it had previously tried to buy some before Blackberry acquired them itself, and that the Finnish firm had also cited related documents in other legal disputes.
The two companies previously clashed in 2012, when Nokia sought to have the sale of Blackberry smartphones banned in the US, UK and Canada in a separate patent row.
Both firms have since stopped designing their own mobile phones and have instead licensed the right to use their brands to other handset makers.