One company, MCI WorldCom, already has agreed to settle charges over ads for its so-called dial-around services, which require callers to dial a string of numbers before placing a call.

The company has reached a consent agreement with the Federal Communications Commission to review its ads for dial-around service and pay $100,000, sources familiar with the case said Tuesday.

Under the agreement, the company will review a year's worth of past ads for dial-around service and submit a report to the FCC, the sources said. Other components of the agreement deal with disclosure of prices for national directory assistance, also a dial-around service, and customer service to answer questions about dial-around.

The agreement comes as regulators have fielded thousands of complaints from consumers about misleading advertising in the long-distance market.

As a result, the FCC and Federal Trade Commission planned to issue a joint policy statement today outlining principles that long-distance companies should follow to avoid enforcement action for deceptive advertising.

"It's too confusing to buy telephone services in America; that's what the public is telling us," FCC Chairman William Kennard said. "The good news is that we have more competition than ever before. Now we have to make sure consumers get the information they need to make an informed choice."

"As the phone business becomes more and more competitive, we get more and more complaints from consumers," Kennard said.

The new policy will assure that callers — including those choosing to use dial-around services with "10-10" numbers — "will have the knowledge they need to select the carrier of their choice and be fairly charged for the services they use," he said.

The new policy contains these elements:

—All claims for long-distance service, including cost, must be truthful, non-misleading and substantiated.

—All costs that may be incurred by consumers should be disclosed, including minimum charges per call, monthly fees, and universal service charges.

—The basis of comparative price claims should be disclosed and only current information should be used in making such claims.

—Information should be disclosed "in a clear and conspicuous manner, and without distracting elements so that consumers can understand it."

The FCC said that it received nearly 3,000 complaints from consumers about allegedly deceptive or misleading advertising by marketers of dial-around service in the first six months of 1999 alone.

Officials said examples include claims of 10-cents-a-minute service "all day and all night" when the rate is actually applicable only for state-to-state calls after 7 p.m. on weekends.

In another example, a marketer conveyed the message that long-distance calls cost a dime a minute and did not disclose the fact that each call is subject to a 50-cent minimum charge.

In a third case, the FCC said, long-distance calls costing a dime a minute are available only to customers who pay a $5.95 monthly fee.

The FCC said that 20 percent of U.S. households have used dial-around services in the last year and that it now represents 7.5 percent of the long-distance market, with revenues reaching $3 billion in 1999.

— Associated Press Writer Kalpana Srinivasan contributed to this report.