or more than a half century, “The Chronicles of Narnia” captivated children with tales of Aslan, a tawny lion who ruled a wintry Narnian kingdom of dwarfs, fauns and occasionally errant English schoolchildren.

Mixing fantasy with Christian allegories and imagery, the author C. S. Lewis, one of the 20th century’s most influential interpreters of Christianity, created a saga that spanned seven novels, beginning in 1950 with “The Lion, the Witch and the Wardrobe,” which have sold more than 65 million copies in more than 30 languages.

Now, borrowing a page from a literary upstart named Harry Potter, the Lewis estate and its publishers have started shaping a marketing makeover of Aslan and assorted Narnian habitués to expand readership and extend the brand.

They have struck deals to license plush Narnian toys. The series publisher, HarperCollins, revealed plans to create new Narnia novels by unidentified authors, to the outrage of some devoted readers. (What next? “Narnia Barbie in a school uniform?” asked one fan in a Lewis electronic forum.)

Most striking of all, they have developed a discreet strategy to avoid direct links to the Christian imagery and theology that suffused the Narnia novels and inspired Lewis.

“They’re turning Narnia into a British version of Mickey Mouse,” said John G. West, co-editor of The C. S. Lewis Readers Encyclopedia and an associate professor of political science at Seattle Pacific University. “What they’ve figured out is that Harry Potter is a cash cow. And here’s a way they can decompartmentalize the children’s novels from the rest of Lewis. That’s what is so troubling. Narnia is a personal creation, and they’re turning it into a corporate creation.”

The publishing strategy surfaced in a HarperCollins memo. “Obviously this is the biggie as far as the estate and our publishing interests are concerned,” wrote an executive from HarperSanFranciso, an imprint of HarperCollins involved in the Lewis publishing program. “We’ll need to be able to give emphatic assurances that no attempt will be made to correlate the stories to Christian imagery/theology.”

The memo was written in connection with the development of a public television documentary about the life of Lewis. The producer, Carol Dean Hatcher, had negotiated contracts to create an illustrated companion book and teaching video for Zondervan Publishing House, the Christian publishing arm of HarperCollins. Zondervan was also poised to donate about $150,000 for the production.

HarperCollins and its publishing arms were in the midst of ambitious expansion plans for Lewis’s works. They repackaged nine classic titles, organized two Web sites (www and www, developed an essay contest and asked contemporary authors to write new forewords. By the fall of 2003 they expected to publish simpler picture books for younger children and a new Narnia novel.

The negotiations over the documentary unraveled, Ms. Hatcher said, amid pressures from the publisher and the estate to eliminate references in the script to Christian imagery in the Narnia series.

“I was appalled,” said Ms. Hatcher, who is still trying to produce the documentary, “C. S. Lewis: An Examined Life,” with Oregon Public Broadcasting as the presenting station. “I think there are ways to approach C. S. Lewis and Narnia that have nothing to do with religious background. However, it is astounding to minimize that part of this; it’s like doing a video biography of Hank Aaron and refusing to acknowledge he was a baseball player.”

For its part, the Lewis estate insists that there is no calculated plan to reshape the author’s image. Simon Adley, managing director of the C. S. Lewis Company, noted that the publishers had successfully increased sales of Lewis’s “Mere Christianity,” an adult title that explains and defends Christianity.

“It’s fatuous to suggest that we’re trying to take the Christian out of C. S. Lewis,” Mr. Adley said. “We wouldn’t have made the effort that we have with `Mere Christianity’ if we felt that way. It’s just crazy. I suppose you could get a little depressed by this. I’m trying to get more people to read.”

But the response from Harper Collins was more ambiguous. Lisa Herling, a spokeswoman, issued a written statement noting that Ms. Hatcher had revealed “confidential in-house correspondence that was part of the incomplete process” involving Ms. Hatcher’s projects.

“One of the issues the correspondence addressed was whether the project would appeal to the secular as well as the evangelical market,” Ms. Herling wrote. “The goal of HarperCollins is to publish the works of C. S. Lewis to the broadest possible audience and leave any interpretation of the works to the reader.”

As a series, the Narnia books are valuable property for HarperCollins, which recently acquired the rights to publish all of Lewis’s works.

Lately, the Narnia series has flourished anew because of the Harry Potter halo effect on young readers searching for something else to read. In the last two years, sales have increased 20 percent annually.

That renewed attention brought new focus on an author untouched by marketing and image-making. Born in Belfast, Northern Ireland, Clive Staples Lewis was a professor of medieval and Renaissance English whose Oxford literary circle, the Inklings, included J. R. R. Tolkien.

In Lewis’s imaginary kingdom, the inhabitants are fauns, talking animals and children who find their way into a secret land by means of a hidden door in a wardrobe. Some plot lines are allegories for Christian themes. Aslan is the Christ figure, the “Son of the Great Emperor Across the Sea,” who defeats the devil figure — the White Witch — through his death and resurrection.

Since Lewis’s death, two movies, both called “Shadowlands,” have explored his life. One starred Anthony Hopkins as the writer and examined his late-blooming relationship with and marriage to Joy Davidman Gresham, an American poet and Jewish atheist who converted to Christianity. Her sons, David and Douglas, ultimately inherited the copyrights to their stepfather’s works after the 1973 death of Lewis’s brother, Warren.

A blunt-spoken, nondenominational Christian preacher, Douglas Gresham lives in Ireland, where he runs Rathvinden Ministries, a country home on 20 acres near Dublin. His brother, David, has played a less active role in the estate and, according to Mr. Gresham, lives in India and has embraced Judaism.

With Mr. Gresham as an adviser, the estate for years generally rejected requests to create sequels or spinoffs to the Narnia series. But that policy shifted as the C. S. Lewis Company took a more active role in managing the copyrights. The company is led by Mr. Adley, formerly a marketing executive at Scholastic, which publishes J. K. Rowling’s Harry Potter series in the United States.

In May Mr. Gresham posted a message in an electronic forum for Lewis fans.

“What is wrong with trying to get people outside of Christianity to read the Narnian chronicles?” he asked, adding, “The Christian audience is less in need of Narnia than the secular audience, and in today’s world the surest way to prevent secularists and their children from reading it is to keep it in the Christian or Religious section of the bookstores or to firmly link Narnia with modern evangelical Christianity.”

HarperCollins is still developing the new Narnia novels and has not announced potential authors. Mr. Adley, of the C. S. Lewis Company, said they would not publish an eighth volume in the series. But they will “fill in the gaps” with the reappearance of some existing characters.

“Increasingly, we’ve found that working in the marketplace we’re competing against new stuff,” he said. “The whole children’s market is geared toward anything new. You can only keep rejacketing something a certain number of times, and in the end you have to produce something new.”