BOSTON — WHEN the 1993 Spanish edition of Laura Esquivel's novel ''Like Water for Chocolate'' unexpectedly sold thousands of copies in a matter of months, it was the incentive many United States publishers needed to tap into the Hispanic market.
By expanding their Spanish-language offerings, or creating whole new lines devoted to such books, a handful of New York's top publishing houses hope to appeal to the more than 26 million Hispanics living in the US.
''Almost everyone in publishing has been on the verge of doing this,'' says Katy Barrett, spokeswoman for Vintage, a paperback division of Random House Inc., which launched its new series of Spanish-language books, Alfaguara-Vintage Espanol, last October.
So far, Vintage's sales have been good, Ms. Barrett says. Two of its translations -- ''The House on Mango Street,'' by Sandra Cisneros and ''When I Was Puerto Rican,'' by Esmeralda Santiago -- have sold about 15,000 copies each. ''There are a lot of titles in English that sell less than that'' she says.
Many factors -- including the increasing Hispanic population and the recent growth of Hispanic print media -- indicate that this is a viable market for book publishers if approached correctly, says Shelly Lipton, president of New York-based Lipton Communications Group, a marketing services company that helps publishers target the Spanish-language market.
''If you carve the numbers and look at purchasing power,'' he speculates, ''it suggests that there is certainly a multi-million-dollar business potential.''
A small selection of Spanish-language books, some imported, have been available in the US for years. But more than 170,000 hardcover and paperback copies of Ms. Esquival's book (published by Anchor Books) are in print. And last fall's Spanish translation of Pope John Paul II's ''Crossing the Threshold of Hope,'' published by Alfred A. Knopf, has sold about 70,000 hardcover copies so far. Such strong sales have gotten the industry's attention.
Despite these successes, Anchor's publisher Martha Levin remain skeptical. She says Esquivel's book was an anomaly because it had a popular English-language edition and movie to boost its sales.
''I've been very surprised by the alacrity with which other publishers have lept into the fray, and I admire their daring,'' she says. ''I'm not convinced that we can make a go of it, which is why I'm doing it title by title.''
Others in the industry are also moving cautiously, but they say the investment is justified.
''If for some reason it doesn't work, I think it was well worth the effort,'' says Christine Lloreda, publisher of Simon & Schuster's new Spanish-language line of books. ''It's a huge market.''
Simon & Schuster/Aguilar -- Libros en Espanol, an imprint that will feature primarily nonfiction books, is being launched in August in conjunction with the Madrid-based publisher Grupo Santillana.
EXECUTIVES at HarperCollins Publishers Inc., who debut their HarperLibros imprint this month with Isabel Allende's first nonfiction book ''Paula,'' acknowledge that they have a lot to learn about marketing to Hispanics. But they say they hope the industry will come-of-age together.
''Instead of one publisher having to be the innovator on its own,'' says Janet Goldstein, an associate editorial director, ''the fact that so many publishers are exploring this is going to open doors for everybody.''
Terrance Gelenter, who created Hispanic Marketing Solutions, in Mill Valley, Calif., last year, says he tells publishers that because of cultural differences, they can't depend on the usual media and distribution channels to reach US Hispanics. For example, publishers need to consider selling their books in nontraditional neighborhood outlets.
''There is no easy way in this market,'' he says, ''but the rewards are phenomenal at the end.''