Shelby Coffey III, a Washington Post writer and editor for the past 17 years, has been named editor of U.S. News & World Report. He replaces Marvin L. Stone, who announced his retirement in January after 25 years at the magazine.

"Shelby will be wonderful. It's a real moment of joy for me and the magazine," said Mortimer B. Zuckerman, who bought U.S. News for $176.3 million last summer. "This is one of the real journalistic opportunities of the decade . . . We'll stay within our traditional and historical boundaries and put out the best magazine we can. There's no magic or mystery involved in this."

Neither Zuckerman nor Coffey would disclose the terms of the contract.

Coffey, 38, is scheduled to meet today with the magazine's staff and may start work as early as the beginning of April. Stone is scheduled to leave the magazine March 31 and it appears likely he will take over the No. 2 spot at the United States Information Agency under Charles Z. Wick.

Benjamin C. Bradlee, executive editor of The Post, said, "Shelby's been a special part of The Washington Post for a long time and we'll miss him enormously. He has a special touch for people and for words which will serve U.S. News very well."

Coffey, one of several top Post editors who have been mentioned as a possible successor to Bradlee, began his career full time at The Post in 1968 as a magazine writer and then became a sportswriter. He gained a number of high-level editorial jobs: editor of the magazine (then called Potomac), assistant managing editor for the Style section, deputy managing editor for features and, for the past two months, assistant managing editor for national news. One of his principal achievements at The Post was overseeing the recent redesign of the paper's format.

Coffey said, "I am honored to have been selected as editor of U.S. News & World Report. Working at The Washington Post for Ben Bradlee has been one of the great journalistic experiences and I leave with regret and affection.

"At U.S. News under Marvin Stone's leadership, the magazine's great traditions have flourished -- traditions that have emphasized solid reporting, clear discussion and responsible analysis. It will be a challenge and a pleasure to follow his distinguished service with the fine staff of this news magazine."

U.S. News, with a circulation of 2.2 million, trails Time (circulation 4.7 million) and Newsweek (circulation 3 million), but its sober approach to the news attracts a highly educated, conservative, prosperous audience, primarily in the Midwest and Sunbelt states.

After buying the magazine, Zuckerman hired former London Times editor Harold Evans as editorial director. Evans has helped redesign the cover and editorial pages but he has maintained that he did not want to become involved in the day-to-day running of the magazine. Zuckerman said that within two months "Harry's major projects with the magazine will have been completed and he'll go back to his primary job, that of editor of the Atlantic Monthly Press."

Before Zuckerman bought it, U.S. News had been staff-owned and, as part of the buy-out plan, Stone is scheduled to be paid $4.2 million. He had been editor since 1976.

The announcement of Coffey as editor should help boost morale at U.S. News, where employes had been uncertain about the editorial control of the magazine. They still do not know when the money for the sale of the magazine will be distributed. A group of former U.S. News employes is seeking a share of the money on the grounds that they were underpaid when they retired. Until their lawsuit is resolved, the distribution of the money may be stalled.

In addition to Coffey, Zuckerman had reportedly talked about the job to several other editors, including Ed Kosner, editor of New York magazine; Stephen B. Shepard, executive editor of BusinessWeek; James D. Squires, editor of the Chicago Tribune; and Bill Kovach, Washington bureau chief of The New York Times.