Overland Park ? Calling collect? Just be sure not to misdial the number for the long-distance carrier.

More than 90 phone numbers that are just digits off several well-known toll free call service numbers, such as (800) COLLECT or (800) CALL-ATT, are operated by a company that will charge as much as three times what the customer would expect from WorldCom Inc. or AT&T Corp., according to a lawsuit filed in New York.

The company that operates those numbers, the lawsuit alleges, is Overland Park-based Sprint Corp., the nation’s third-largest long-distance carrier. The lawsuit claims Sprint even runs variations of its own (800) ONE-DIME and (800) FON-CALL.

The lawsuit filed by Brooklyn, N.Y., resident Joel Drizin in January after he received a $16.42 bill for a four-minute call from his brother-in-law in New Jersey alleges that Sprint, through its subsidiary ASC Telecom Inc., uses “deceptive business practices” to defraud customers. Drizin and his attorney and friend, Robert Tolchin, are now working to have the lawsuit certified as a class-action complaint.

The practice of misdialing or misspelling phone numbers is known in the telecommunications industry as “fat fingers” dialing.

Sprint claims that neither it nor ASC actually owns the numbers, though it would not disclose who does. The company said it operates the numbers for others in accordance with federal laws.

The Federal Communications Commission has received complaints about companies that own these 1-800 numbers, said Robert Mirelson, deputy bureau chief for consumer affairs. But he refused to name those companies.

Mirelson said the FCC has asked some companies “to be more forthcoming” when people call. It also is warning consumers about the practice and telling them to be careful.

“If you have an operator in the call process, question, ask what company you’re dealing with,” Mirelson said. Callers should hang up and redial if they don’t reach an operator, or if the operator won’t identify the company, he said.

According to Drizin’s lawsuit, callers who try to reach AT&T, WorldCom, Verizon Communications, BellSouth Corp. and Sprint can misdial and end up with ASC.

For example, instead of dialing (800) 225-5288 to reach AT&T, a person might accidentally dial (800) 225-5528 and reach ASC Telecom, the lawsuit says. Callers mistakenly substituting the number 0 for the letter O in WorldCom’s (800) COLLECT would also reach ASC.

Tolchin said that if people knew who they were calling and what they would be charged, “no rational person would ever use the service.” Tolchin estimates that Sprint has bilked hundreds of millions of dollars out of customers through ASC, though Sprint has sternly denied misleading anyone and says ASC’s operation of the numbers, for others, complies with federal law.

Tolchin said he has not seen billing records from Sprint or ASC to quantify his claims of large consumer losses resulting from misdialing.

Drizin said he filed the lawsuit because he was angry. He claims his brother-in-law was trying to use WorldCom, which would have charged just $6.19 for the phone call last November.

“It was an obvious scam. I don’t like to be taken,” Drizin said. “When people say, ‘It’s the principle; it’s not the money,’ it’s usually the money. Well, in this case it’s the principle.”

Sprint officials would not comment on the lawsuit. However, the company issued a written statement saying the allegations “are entirely unfounded” and that the numbers in question are “obtained and used by third parties.”

“ASC provides billing and other services to these third-parties and is compensated for providing those services,” the statement said. “However, neither Sprint nor ASC control the 800 numbers and by law are not allowed to monitor those numbers. Sprint does not control which customers obtain which toll free numbers or how customers use those numbers. Neither Sprint nor its affiliated companies, including ASC, own any of the telephone numbers alleged in the lawsuit to be similar to those offered by other carriers.”

Federal laws meant to promote competition require telecommunications companies to provide access to their networks to other companies, but they don’t have to provide customer service and billing.

Tolchin said that while it’s true that people can buy 1- 800 numbers through long-distance carriers and operate them as they wish, Sprint is more involved than that in this case.

“Their operators are answering the phone. Their operators are the ones actually doing the deceiving. There’s no law that says that if someone asks you to defraud someone else that you have to do that,” he said.

Many people don’t complain because it’s easier to pay the bill, Tolchin said. Also, ASC often reduces bills for those who do complain, he said.

He said Sprint is taking advantage of the most vulnerable: children, the elderly, the disabled, people who don’t speak English well and of course those with large fingers.

“It’s the kind of thing you’d expect from a carnival huckster,” he said.