[Nokia says in a recent court filing it has paid $1 billion over 15 years for access to Qualcomm patents and they are now paid up and royalty-free.]

by Tarmo Virki, Helsinki (Reuters) -- Nokia has paid Qualcomm around $1 billion over 15 years for full access to the U.S. chip maker's early mobile technology patents, the world's top handset maker said in court documents.

Nokia said in a public version of a court filing in Delaware that the patents are now paid up and royalty-free, according to the terms of 1992 and 2001 agreements with Qualcomm.

Qualcomm was not immediately available for comment.

The companies have been at legal loggerheads since failing to renew a technology license pact that expired on April 9, 2007. Analysts estimate that Nokia pays around $500 million a year for use of Qualcomm patents and it wants to reduce the sum.

Qualcomm has said that by continuing to ship products using its patents Nokia has agreed to continue on the same terms, but Nokia said in the court filing that the deals between the two firms say the cross-licensing agreement can only be extended in writing.

The companies have not disclosed the timeframe of so-called "early" patents, which stem from Qualcomm's time as the leading developer of CDMA wireless technology.

CDMA technology, widely used in the United States and some Asian countries, failed to gain global adoption when competing against European GSM technology -- but it has gained wider adoption in later, third-generation forms.

Nokia and Qualcomm have more than a dozen legal fights pending on three continents.

Analysts see these cases as efforts by both companies to gain leverage in the terms of an eventual license-pact renewal. But their expensive legal battles have worried investors on both sides of the Atlantic.

(Reporting by Tarmo Virki; Editing by David Cowell)