Travel and real estate giant Cendant said Monday it'll split itself into four companies, a move designed to boost its stock market value.

"The sum of the parts has a value in excess of our current share price," CEO Henry Silverman said in a conference call. New York-based Cendant, a franchise giant with holdings that include Century 21, Orbitz, Ramada and Avis brands, will replace its shares with those of the newly created companies. The formula for the swap, to be completed in summer 2006, is yet to be determined. It won't affect customers or employees, Cendant said.

Cendant plans to spin off three units -- real estate, hotels and travel services -- into separate, publicly traded companies. Cendant itself will retain its car rental brands, Avis and Budget. All four companies will be renamed. Silverman will run the travel company. Other Cendant executives will head the others.

Silverman said the company's accomplishments "have not been fully appreciated by the market." Separate, better-focused companies could change that.

Cendant was created in 1997 by the merger of HFS and CUC International. Cendant disclosed in 1998 that CUC was involved in what was then the largest accounting fraud in history, having overstated earnings for several years. The stock never fully recovered, and it is down about 20% year to date.

Cendant's move reflects a corporate trend to downsize as a way to "unlock" value for business units. Earlier this year, Barry Diller-controlled IAC/InterActive spun off Expedia, an online travel company, dividing its e-commerce businesses into travel and non-travel units.

Viacom, a media conglomerate, said this year it'll separate into two companies -- one with cable and film studio businesses, the other with radio and TV operations. Share values for IAC, Expedia and Viacom are down for the year.

Investors slammed Cendant shares Monday. The stock closed at $18.77, down 6.6%. Citing travel disruptions caused by Hurricane Katrina, Cendant said its third-quarter earnings fell from a year ago. Earnings for 2005 will be lower than expected, it said.

Ivan Feinseth, analyst at Matrix USA, said poor earnings outweighed the news of the split-up with investors.

"You can't correct poor corporate performance through financial engineering," Feinseth says.

Tom Lys, a business professor at Northwestern University, says the better focus of separate units may appeal to investors. Conglomerates trade lower than comparable companies with fewer business lines, he says. They "are not that focused or hungry."