One of the few areas of growth in an otherwise stagnant business.

Forget about agents and auctions and multimillion-dollar contracts. The stiffest competition in the book business may be among the many publishers staking claim to Dickens, Austen, Herodotus and Plato.

Selling the classics is one of the few areas of significant growth in an otherwise stagnant business. Major publishers, including Penguin Group USA and Bertelsmann, are aggressively defending their lucrative share of both the consumer and academic markets by investing heavily in redesigning and expanding their classics lists.

Imprints like Penguin Classics, the market leader, as well as Modern Library and Bantam Classics, two units of Bertelsmann, depend heavily on literary works in the public domain. In a fiercely competitive market, where one copy of "Pride and Prejudice" can seem the same as any other, they vie not only with one another but with Barnes & Noble, which sells its own editions of classics and displays them at the front of its stores.

In January, Penguin Classics began a $500,000 promotion to kick off a two-year global program under which its entire 1,300-book list of classics, the industry's largest, will receive a complete facelift.

"Penguin Classics has always been a sizable percentage of our business," said Kathryn Court, president of Penguin Books. "We determined in the last couple of years to reinforce our brand identity."

Court would not provide sales figures but said 2002 revenue for Penguin Classics was 13 percent higher than in 2001.

Sales of the classics have risen, retailers say, because of reading groups and an aging population. Increasingly, many editions include reading group guides.

"I hate to bring the boomers into every discussion, but a lot more adults are going back to the classics because of reading groups," said Bob Gray, bookseller and buyer at Northshire Books in Vermont.

"People shopping the classics have been seeing the same books for what may be their entire lives," Gray added. Because of Penguin's redesign, he said, "Now their eyes will no longer glaze over; it will probably make them stop."

For the first time, Penguin will also publish many modern classics, by John Steinbeck, Jack Kerouac and others, under the Penguin Classics imprint, discontinuing its Twentieth-Century Classics line.

"Three types of Penguin books are now one type of book," said Penguin's marketing director, John Fagan. "Moving to one spine increases the presence of the line visually."

The stakes are getting higher. In 2000, Modern Library introduced a series of paperback classics that many in the industry saw as an attempt to chip away at Penguin's dominance. But the bigger threat may be Barnes & Noble's editions.

"B&N classics — that's where Penguin is probably feeling the pressure," said an executive who insisted on anonymity.

Barnes & Noble would not comment on its publishing program, but Bob Weitrak, the retailer's director of merchandising, said: "We've always carried Penguin Classics. They are extremely good sellers."