MCI Communications Corp.'s use of third-party sales agents such as Amway Corp. is resulting in widespread consumer abuse, the Communications Workers of America has contended.

"The sales competition among providers of long-distance telephone service is leading, in some cases, to marketing practices that harass, deceive and defraud the American public," said Morton Bahr, president of the communications-worker's union, in a letter to Federal Communications Commission Chairman Mark S. Fowler.

"An example is MCI Corp.'s reliance on Amway and independent telemarketing groups to market its long-distance services," he wrote.

MCI Communications Corp. spokesman Gary Tobin attributed CWA's complaint to union problems involving CWA, AT&T and the seven regional phone companies. "They've got an issue -- employment -- and rather than working toward solving their problems with AT&T, they are trying to bring in a third party," he said.

MCI hired Amway last October to market its long-distance service door-to-door. Competition among long-distance companies has been particularly fierce because of a nationwide process of providing customers with Dial-1 long-distance service, which allows customers to place calls through alternative long-distance companies without dialing a long series of extra numbers.

Bahr said in his letter that the CWA has reviewed FCC files and found "letter after letter reporting deliberate, unauthorized conversion to MCI service; unwarranted charges to 'reconvert'; financial loss resulting from inadequate and unauthorized service; repeated and harassing telephone solicitation; deceptive offers to convert . . . and other unacceptable marketing practices."

Rick Braswell, an organizer for CWA, said the organization did not think MCI marketers were at fault but instead blamed Amway and other "third-party, boiler-room operations" MCI has hired for high-pressure sales tactics.

"It's bad for consumers and for MCI workers," who are displaced by Amway representatives who do not get paid or receive benefits, Braswell said. Amway representatives are paid by commission.

"We haven't been notified of any such complaints by either the union or the FCC," said Peit Bennett, an Amway spokesman. "I am absolutely in a quandry."

Tobin said: "Between last July and January, there were a total of seven complaints to the FCC about Amway.

"There are 600,000 Amway distributors and millions of potential customers -- if there are only seven complaints, there is probably no cause for concern."

Tobin dismissed the accusation that MCI uses "boiler-room operations" to sign up customers.