NORTH MUSKEGON, Mich. - A "Harry Potter" fan and website operator said Friday he's going ahead with publishing an encyclopedia, despite losing a copyright-infringement lawsuit filed by the author of the massively popular book series.

Steven Vander Ark said during a news conference at a bookstore that Muskegon-based RDR Books will publish "The Lexicon: An Unauthorized Guide to Harry Potter Fiction and Related Materials" on Jan. 12.

Author J.K. Rowling and Warner Bros., maker of the Harry Potter films and owner of intellectual property rights to the Potter books and movies, sued RDR Books in 2007 to stop the publication of a similar volume by Vander Ark.

A federal judge in New York ruled in favour of Rowling in September, permanently blocking publication of that reference guide. He also awarded Rowling and Warner Bros. Entertainment Inc. US$6,750 in statutory damages.

RDR Books appealed the court ruling last month but withdrew the appeal on Thursday.

Vander Ark, a former school librarian who launched The Harry Potter Lexicon website in 2000, and his publisher say the revised version meets specifications for such a book laid out in the judge's ruling. He said he spent five or six months working on the revision following the three-day court hearing in April.

During the trial, the small publisher did not contest that the lexicon infringes on Rowling's copyright, but argued it was a fair use allowable by law for reference books. The judge ruled Vander Ark went too far.

When he blocked publication in September, U.S. District Judge Robert P. Patterson said the "lexicon appropriates too much of Rowling's creative work for its purposes as a reference guide."

"We learned a lot at the trial about what was acceptable, what would follow the fair use guidelines," said Vander Ark, 50. "That was not clear before. There was no law on the books that made it clear what was acceptable and what wasn't.

"So, coming out of the trial, I had a much better idea of what should go into the book."

RDR Books publisher Roger Rapoport said the biggest difference between the two versions is that the revision contains "a lot more critical commentary, which means more analysis."

"It isn't just saying what happens, it's his interpretation of why it's important," Rapoport said.

Vander Ark also removed plot spoilers from his book, in adherence to the court's instructions, Rapoport said.

"We are delighted that this matter is finally and favourably resolved and that J.K. Rowling's rights -- and indeed the rights of all authors of creative works -- have been protected," said Neil Blair, a lawyer for Rowling's London-based agent, the Christopher Little Literary Agency.

"We are also pleased to hear that rather than continue to litigate, RDR have themselves decided to publish a different book prepared with reference to Judge Patterson's decision."

Vander Ark worked for 15 years as a teacher and librarian at Byron Center Christian School near Grand Rapids before resigning in October 2007 to become a full-time writer.

Though Rowling had once praised Vander Ark's website, she testified earlier this year that the lexicon was nothing more than a rearrangement of the material.

Rowling's "The Tales of Beedle the Bard" became available Thursday. It's a collection of five fables mentioned in her saga about the boy wizard.