The estate of author J.R.R. Tolkien and Rupert Murdoch's HarperCollins Publishers sued the producer of the Lord Of The Rings movies, New Line Cinema, on Monday in a fight over profits from the blockbuster trilogy.

The trustees of the writer's British charity, and News Corp's HarperCollins cited a failure to pay a contractually agreed 7.5 per cent of gross profit for the three films based on the Lord Of The Rings novels.

The suit follows Rings director Peter Jackson's lawsuit against New Line for underpayment that was settled in December. When that deal was finalised, Jackson signed on to be executive producer of The Hobbit, also based on a Tolkien novel.