A top management committee of United Press International has proposed paring its domestic editorial staff by more than 45 percent from levels of last October, according to a confidential memo obtained by The Washington Post.

UPI executives, faced with losses of more than $1 million a month, asked owner Mario Vazquez Rana to sign off on a plan to cut the domestic editorial staff to 640 by the end of January with a goal of bringing the staff down to 484 positions.

The staff totaled about 900 in early October, but with resignations and layoffs, UPI's domestic wire now employs about 700 people, according to UPI sources and the Wire Service Guild.

The proposal for a second round of cuts has caused what one Guild spokesman, Dan Carmichael, called "internecine warfare" at the top levels of UPI. Sources said that some managers are warning Vazquez Rana that the wire service could not continue with so few reporters and editors on its domestic staff.

The author of the memo, UPI executive editor Claude Hippeau, said in a statement: "While UPI has laid off some employees over the last several weeks, current domestic editorial employment remains well above a figure like 640."

Calling the numbers in the memo "invalid," he said that UPI's management has spent long hours over the last several weeks reviewing "a wide range of largely hypothetical options. Many of these we have now discarded."

"I can say that we believe it is critical to get UPI on a sound financial footing for the future," Hippeau said. "Once we have succeeded at this task, most of the questions now being asked -- hypothetical or otherwise -- are no longer very significant."

Written on Dec. 30 to Vazquez Rana, the memo proposed the deeper cuts as part of a two-phase restructuring of the wire service, some of which has already been put into effect. Hippeau's letter to Vazquez Rana said that he wanted to start with domestic cuts and give further study on how to stop deficits in the English-language international divisions.

UPI spokesman Christopher Smith announced earlier this month that UPI would be restructured by scaling back operations in some bureaus and offering different ways of packaging services to clients. He has said that instead of "every news story, every fact and figure," UPI would focus on major events.

In what some UPI veterans call an "unbundling" of the service, UPI managers are also considering selling services separately -- photo, for example, or sports. Previously a client bought the entire UPI package.

Carmichael said last week that there had been at least 110 job terminations since Nov. 1 and at least 14 domestic bureaus closed, including Wichita, Kans.; Frankfort, Ky.; Rockford, Ill.; Portland, Me.; Reno, Nev. and West Palm Beach, Fla.