Financially troubled United Press International's fate is still unsettled.

Reuters Ltd., the London-based news service that first expressed interest in acquiring UPI last May, is still considering such a move. Meanwhile, the name of another potential buyer of the news service has surfaced.

Richard Mellon Scaife, a great grandson of the founder of the Mellon empire, has had several conversations with UPI's owner, E.W. Scripps Co., according to a Scripps official.

Scaife, who is 49 and lives in Pittsburgh, owns several small Pennsylvania papers and the Sacramento Union in California. The publicity-shy Mellon heir could not be reached for comment. His closest aide, Richard Larry, did not return several phone calls.

Clyde Slease III, a Scaife attorney in Pittsburgh, said he doubted the report. "I couldn't confirm or deny it, but I would put my answer more on the denial side," Slease said.

The predecessor to the modern-day UPI was established in 1907 by E.W. Scripps, founder of the Cincinnati publishing company. For the past two years, the company has been looking for a buyer for its news service, which ranks behind the Associated Press in the number of news organizations it serves.

According to a recent article in Business Week, UPI has been unprofitable for the past 25 years and expects an after-tax loss this year of about $4 million.

Reuters officials have visited 64 UPI bureaus and subscribers in this country since expressing interest in acquiring the wire service. "We're still considering and analyzing the results of the investigation," said Richard Maberley, managing editor of Reuters in the United States.

UPI executives had hoped that a deal with Reuters could be worked out in time for this week's annual Edicon meeting of editors and publishers whose newspapers subscribe to the UPI news service.

But Edward W. Estlow, president and chief executive officer of Scripps, made it clear in a press release issued at the New York meeting that no sale is imminent. He also said that other potential buyers of UPI had been speaking with Scripps but that "their method of analyzing had been more subtle" than Reuters'.

That comment by Estlow apparently was triggered by concern that has spread through the UPI organization because of the tough questions being asked by the Reuters team.

The executive editor of a major Texas newspaper who was interviewed by the Reuters officials said the Reuters people were seeking advice on what course they should take.

"Their questions dealt with whether they should acquire all of UPI and meet AP head on, or just devise a niche for themselves," said Burl Osborn, vice president and executive editor of the Dallas Morning News. "They wondered whether they should watch UPI fold, then expand on their own, or should they acquire only parts of UPI, such as the wire and photo service, and not the broadcasting part."