Fire officials said an electrical short in an extension cord used by the Pearl nightclub started a small fire in an Ala Moana Center storage room that was quickly doused yesterday.

However, water seeped from an automatic fire sprinkler system into the Barnes & Noble Bookseller store on the center’s street level below, causing extensive damage to books and display equipment.

Water also flowed into the store’s storage areas on the center’s coral level.

Carolyn Brown, a New York spokeswoman for the book company, said in an e-mail that the company does not plan to disclose any damage figures.

The bookstore, which was scheduled to open at 9 a.m., opened instead at about 11:45 a.m. after the damage was cleaned up.

The fire was reported at 7:54 a.m. as being in a storage room on the mall level. Firefighters arrived at 8:01 a.m. and had it under control 10 minutes later. Fire officials set damage to the storage room and its contents at $5,000.

Pearl’s storage room is behind the Fendi woman’s apparel store on the mall level. Although Fendi was not damaged by the fire, a strong odor of smoke lingered after it was extinguished.