Kenneth W. Starr yesterday officially relinquished control of his five-year investigation into President Clinton, passing the baton to a top assistant, Robert W. Ray, who was sworn in to succeed him.

Starr submitted his resignation to the three-judge panel that had appointed him, ending a tenure that generated 14 criminal convictions, the impeachment and acquittal of the president, and a cascade of criticism from Democrats. In his resignation letter, Starr complained about "the intense politicization of the independent counsel process."

"To reduce the unfortunate personalization of the process, in particular in the wake of the inherently divisive impeachment proceedings, the wiser course, I believe, is for another individual to head the organization," he wrote.

Starr, who has talked of returning to his private law practice for months, initially had asked the Justice Department to take over any issues remaining from his probes. But the Justice Department declined to do so, and Starr began pushing for the appointment of one of his top deputies to succeed him. Although Congress allowed the independent counsel statute to expire last summer, those investigations already under way were permitted to continue.

Ray, 39, yesterday vowed to "live up to the finest traditions of what it means to be a professional prosecutor" and carry out his duties in a "prompt, responsible and cost-effective manner." Ray joined Starr's office in April, after a four-year stint working on independent counsel Donald Smaltz's investigation of former agriculture secretary Mike Espy, who was acquitted of corruption charges last December.

Starr, whose investigations have cost more than $47 million, leaves Ray with some critical unfinished business, including questions about whether Democratic fundraiser Nathan Landow tampered with potential witness Kathleen Willey in the Paula Jones sexual harassment case and whether any crimes were committed in the White House travel office scandal.

Ray also will oversee the preparation of a final report summing up the office's many investigations, which cover activities dating to the Clintons' days in Arkansas. Depending upon its timing and content, the report could emerge as an issue in next year's presidential race or in Hillary Rodham Clinton's anticipated Senate campaign.

Noting Ray's role in the Espy case, the White House immediately questioned his promotion last week. But Ray also has years of experience as a successful federal prosecutor in New York, where he helped win convictions that dismantled a gang believed responsible for 80 homicides.

Flanked by his family, Ray was congratulated moments after the private swearing-in by numerous colleagues from Starr's office. Starr himself did not attend the ceremony, but Ray made a point of praising his "extraordinary service to the country at great personal sacrifice."

Despite the celebratory air, the appointment of Ray again exposed tensions within the three-judge panel of the U.S. Court of Appeals that oversees independent counsel investigations. A division first became apparent in August when Senior Judge Richard D. Cudahy said it was time to end Starr's investigation.

Yesterday Cudahy revisited the matter, saying that the judges decided to select someone from Starr's office to replace him rather than an outsider in order to avoid further delays in wrapping up matters. "There can be no more vital consideration now than closure with all deliberate speed," wrote Cudahy, who was appointed to the federal bench by President Jimmy Carter.

Cudahy's view was challenged by fellow Senior Judge Peter T. Fay, a Nixon appointee, who wrote that Ray will be expected to conclude the investigation "regardless of how much time is involved." Fay added that the court should not attempt to instruct independent counsels on how to conduct their business.

Starr referred to the judicial disagreement in an interview with CNN yesterday, declaring that allegations that he had been overzealous were "bogus, totally made up, without foundation."

"My job was to carry out the assignment given to me. . . . And that's exactly the point of the politicization," Starr said. "Even the judges have found themselves embroiled in the politics of this process."

Staff writer Lorraine Adams contributed to this report.