United Press International has begun talks with representatives of Yomiuri Shimbun, Japan's largest newspaper publisher, about the sale of a minority stake in the financially beleaguered news wire service, sources familiar with the discussions said yesterday.

Yomiuri is one of several parties that have discussed an investment in or the purchase of UPI since late November, according to the sources, who spoke on condition they not be identified. Other potential bidders were not disclosed, but they are said to include companies based in the United States, Japan and Western Europe.

UPI spokesman Milt Capps declined to comment on the discussions. Asked about Japanese involvement, however, he said, "We can say at this point no Japanese parties are seeking controlling interest." Capps added that the Washington-based news organization "had no guarantees that any deals will be concluded."

Yomiuri Shimbun also owns the Yomiuri Giants baseball team, technical and cultural centers, country clubs and an amusement park.

Yasuo Suzuki, foreign editor of the Yomiuri, said this morning that he was unaware of any discussions. "I have never heard of this story," he said. "Although I am not part of top management, it is quite inconceivable that a foreign editor would not be aware of such a project."

UPI, which is owned by Infotechnology Inc. of New York, has been seeking a joint venture partner or a buyer since October when Infotechnology replaced its chief executive and began searching for ways out of a financial crisis.

Staff writer Paul Blustein contributed to this report from Tokyo.