United Press International, struggling to survive continuing losses as it attempts to rebuild, has found a major new client: the U.S. government's foreign news outlet.

On Friday the wire service will begin transmitting the U.S. Information Agency's news and features services from Washington to 33 newsrooms in six European cities, the first phase of a two-year, $2.5 million contract that calls for UPI to send the government's news directly to media outlets in 32 foreign cities.

Several journalists and journalism professors complained yesterday that the UPI service creates ethical problems and is certain to blur the separation of the American press and the U.S. government.

"I would say it is doubly ironic," said Michael G. Gartner, a former president of the American Society of Newspaper Editors and a Gannett Corp. news executive. "First of all that an American wire service would take on as a client an agency of the U.S. government, and that it is distributing overseas material that it is illegal to distribute in the U.S."

James Hood, a UPI vice president, defended the contract in an interview and said it will "absolutely not" create any ethical problems for the privately owned wire service.

Hood said the USIA wire "will have nothing to do with UPI news. It's what we call, in wire service jargon, third-party traffic."

The USIA material will be transmitted on circuits separate from those used by UPI news services and will be printed on machines that will not be marked with the UPI logotype, Hood said.

"We all deal with the government a lot," he said. "We sell them our news service. I don't think our providing communication facilities for the government is any different than The Washington Post selling an advertisement to the D.C. Police Department about the sale of confiscated cars."

The USIA service that UPI is transmitting consists of news and features prepared by the information agency as well as the text of statements from the White House and State and Defense Departments.

The journalists who questioned the UPI contract said that the distinction between news and advertising material in U.S. newspapers is different from a financial relationship between a news organization and the government.

"No matter how carefully it is disguised, somebody . . . is going to raise a question about the relationship," said Howard Simons, curator of the Nieman Foundation at Harvard University and a former managing editor of The Post.

Carl Sessions Stepp, an assistant professor of journalism at the University of Maryland and a senior editor of the Washington Journalism Review, said that many people overseas have difficulty seeing the distinction between the U.S. media and the U.S. government and that the service may add to the confusion. "It's one more way a coziness grows between the government and the press," he said.

For years, the USIA press service, known as the agency's "wireless file," has been distributed by USIA officers who have received the material via government cable traffic and hand-carried the material to newspaper and broadcasting offices in hopes it will be used. The agency is banned by law from distributing any of its news or information products in the United States.

Under USIA Director Charles Z. Wick, the agency has embarked on an aggressive program to modernize it facilities and a spokesman for the agency described the UPI service as "just another aspect of using high tech to get the word out."

USIA officials said that UPI won a contract for the service last year in a competition with MCI Communications, a major communications company. The contract runs for two years and has an option for a third year.

"Our job is to tell America's story overseas," said USIA spokesman William B. Reinckens. "We expect this to improve effectiveness and speed the delivery of the news."

He described the wire service as an American counterpart to Tass, the government-run news service of the Soviet Union. Stories on the USIA service carry bylines identifying the writers as "USIA correspondents."

The first cities to receive the service are London, Rome, Copenhagen, The Hague, Brussels and Ankara, Turkey. In London, the clients are BBC Radio and Jane's Defence Weekly; in Rome, ANSA, the Italian news service; in The Hague, ANP, the Dutch national press agency; and in Ankara, nine media outlets.

The service is available in French, English, Arabic and Spanish.