Wal-Mart Stores' online shopping site suffered a brief outage Wednesday when an unexpectedly high number of anxious Christmas shoppers flocked to the site looking for the hard-to-find Elmo T.M.X. doll.

The retail company didn't disclose details, but said in an e-mail that Wal-Mart.com experienced an "incredibly high traffic volume" when the doll went on sale. It was sold out within a matter of minutes.

"This higher-than-expected traffic spike caused a brief site outage," Wal-Mart spokeswoman Amy Colella said.

Wal-Mart apologized to customers for the inconvenience and said it had corrected the problem to avoid a similar outage in the future. The hugely popular Elmo T.M.X would be available again at various times Thursday and Friday, Wal-Mart said.

Elmo is a character in the kids TV puppet show Sesame Street on PBS. When activated, the battery-operated toy has the character falling and squirming in fits of laughter.