On his third day of testimony in a London court yesterday, Dan Brown acknowledged "reworking" passages from another book for his best-selling novel "The Da Vinci Code," but rejected charges that he stole key ideas for his thriller, The Associated Press reported.

He was testifying on behalf of his British publisher, Random House U.K., in a copyright infringement suit brought by two of the three authors of a 1982 nonfiction book, "The Holy Blood and the Holy Grail," also published by Random House. Mr. Brown called the accusation that he copied the thematic "architecture" of that book — which, like "The Da Vinci Code," posits a conspiracy to protect the secret of Jesus' bloodline — "completely fanciful." Patrick Janson-Smith, a literary agent who was involved with both books when he was the publishing director of a division of Random House, testified that he saw similarities between them but no evidence of copying. " 'The Da Vinci Code' is "a romping piece of good fiction," he said. "Like any thriller," he added, "no doubt it took ideas from any number of sources."