NEW YORK (Reuters) - Pop star Rihanna has agreed to settle a lawsuit with her former accountants accusing them of mismanaging her finances and costing her millions of dollars, lawyers for the parties told a federal judge on Thursday.

The terms of the deal were not disclosed during a brief hearing before United States District Judge Kevin Castel in New York. Lawyers for Rihanna and for the defendants, accounting firm Berdon and former employees Michael Mitnick and Peter Gounis, declined to comment.

The lawsuit, filed by Rihanna in 2012, said Berdon charged "exorbitant" commissions from her concert tours, causing significant financial losses. It also accused Berdon of mishandling Rihanna's foreign and domestic taxes and failing to monitor unpaid song royalties.

The Barbados-born Rihanna, 26, whose real name is Robyn Fenty, is one of the world's most successful recording artists, with a string of worldwide hits including the singles Umbrella and Diamonds. She has won seven Grammy Awards.

When she first hired Berdon, the lawsuit claimed, she was only 16 and knew nothing about financial matters.

As a result of the firm's mishandling of her finances, she suffered major losses during her 2010 Last Girl On Earth tour, even as Berdon collected millions of dollars in commissions, the lawsuit claimed.

Spokesmen for Rihanna and for Berdon were not immediately available for comment.