Two authors who unsuccessfully sued the publisher of "The Da Vinci Code" for copyright infringement have been given permission to challenge their defeat in court, court officials said Wednesday.

The Court of Appeal said Judge Timothy Lloyd had granted Michael Baigent and Richard Leigh permission to mount a legal appeal. No date has been set for the hearing, which is expected to begin late this year or early in 2007.

In April, a High Court judge rejected the pair's claim that Dan Brown's blockbuster thriller stole central ideas from their 1982 nonfiction book "The Holy Blood and the Holy Grail." Judge Peter Smith said the claim had been based on a "selective number of facts and ideas artificially taken out of (the book) for the purpose of the litigation."

Smith ruled that "The Da Vinci Code" had copied some language from "The Holy Blood and the Holy Grail," but said it did not amount to copyright infringement.

Both books explore theories that Jesus married Mary Magdalene, the couple had a child and the bloodline survives.

The media-shy Brown traveled to London to give evidence in the case on behalf of his publisher, Random House.

In a statement, Random House said it respected Baigent and Leigh's right to appeal, but regretted "that more time and money is being spent trying to establish a case that was so comprehensively defeated in the High Court."

"The Da Vinci Code" has sold more than 40 million copies — including 12 million hardcovers in the United States — since its release in March 2003. A film version starring Tom Hanks was released in May.

"The Holy Blood and the Holy Grail" — also published by Random House — was a best seller on its release, and climbed sales charts again thanks to publicity surrounding the case.