Edward M. Rogers, top aide to White House Chief of Staff John H. Sununu who was expected to play a key liaison role in the 1992 presidential election campaign, is making plans to leave the administration to open a law practice.

Rogers, 32, has served as Sununu's chief political liaison and enforcer in the White House, working with party operatives and campaign officials. Before that he had been chief aide to Republican National Committee Chairman Lee Atwater during the 1988 campaign.

Rogers, who has a law degree from the University of Alabama, would not comment on his plans, but White House sources said yesterday he has discussed with the legal counsel's office the opening of a law firm with another Republican political operative, Haley Barbour, who has a law practice in Washington and Mississippi.

An official said Rogers's departure plans are not firmly set but he is expected to leave by spring. The official said his departure is amicable despite a rocky political season last year in which he played a key inside role in the contentious GOP campaign and in the awkward selection of a successor to Atwater.

Rogers became the target of resentment in the White House and among Bush loyalists outside the White House in part because of his monitoring the news media for anonymous quotes criticizing Sununu and then attempting to track down the source. Numerous Republicans had complained of Rogers's calls on Sununu's behalf, accusing them of criticizing the chief of staff. Rogers had become known as the "highlight king" for his habit of marking offensive quotes with yellow marker pens.

Officials suggested it was unlikely Rogers would have a full-time participation in the reelection effort but could seek a consulting role. His departure leaves vacant a pivotal White House spot for a political operative as the coordinating point between the White House and a 1992 campaign.