For the past three days, Sahar Sarid thought he might become a very, very rich man.

Early Saturday morning--about 4 a.m. Texas time--the 25-year-old computer programmer was sitting at his terminal trying to think of Internet domain names that he could buy for the standard $70 fee and sell at a huge profit to large corporations desperate to market their online sites with punchy names.

That day, Sarid registered: shoppingforhim.com, shoppingforher.com, medicalmd.org, adoptionclinic.net, constructionahead.net and 11 others.

Then on a whim he tried aol.com and aol.net, which he figured already were owned by America Online Inc.

But to his surprise, Register.com, a domain registration site based in New York City that competes with Herndon's Network Solutions Inc., reported that the two names were still available.

Sarid immediately signed up.

A few minutes later, he received a cheery e-mail that said: "Congratulations on your new domain name!" His credit card (actually, his mom's) was charged $140 for both names. He checked the online registry of domain names called Whois just to verify his good fortune and the service did indeed list him as the owner of aol.com and aol.net. He made calls to friends and family members bragging about his acquisition.

Then, he went to sleep.

Sarid tried to buy about 50 names this past week after reading a news article about the millions of dollars Internet "name brokers" have made in recent months. The Israeli immigrant who now lives in Magnolia, Tex., says he wasn't specifically hunting for an America Online domain, but stumbled on aol.com while looking for a Web address to use for a synagogue guide he calls Angels of Love.

He found out only yesterday that America Online had purchased those names years ago.

Register.com spokeswoman Shonna Keogan blames the misunderstanding on a computer glitch. She said the central registration database--shared by the five companies authorized by the Internet Corp. for Assigned Names and Numbers, a nonprofit set up by the federal government, to sell the names--was down at one point over the weekend and couldn't verify whether names had been registered or not.

The Whois information was corrected about 4 p.m. yesterday.

America Online spokeswoman Tricia Primrose was surprised to learn of the temporary problem but emphasized that the mistaken sale was only a "paper transaction" and did not affect AOL's service. "We have owned and continue to own aol.com," she said. "At no time did the ownership of aol.com pass into unauthorized hands."