D.C. Superior Court Judge Donald Smith retired yesterday in an unexpected move, four months after surviving a contested renomination process that focused on allegations of racial insensitivity and intemperate behavior on the bench.

The city's judicial oversight commission appointed Smith, 58, to a second 15-year term in May and praised him for his "outstanding record of judicial performance," but it said at the time it planned to monitor his behavior as a result of a "significant" number of complaints it had received about his demeanor.

Smith notified the judicial nomination commission, a separate committee, of his plans to retire in a one-sentence letter last month.

Smith could not be reached for comment yesterday, but judges who know him said a number of factors appear to have influenced his decision to retire at this time, including frustration over the "backhanded" renomination as well as the ability to qualify for greater retirement benefits.

"I thought after enduring all the slings and arrows of the tenure commission he would have stayed on," said a judge, reflecting the sentiment of several other jurists and lawyers who were caught off guard by Smith's retirement.

Other judges said Smith had been surprised and angered by the oversight commission's public criticism of his tenure. The oversight commission investigates complaints of judical misconduct and reviews the reappointment of judges.

In its evaluation released in May, commission members praised Smith's legal scholarship and said they had not found "sufficient evidence to sustain" the allegations. Despite its finding, however, commission members said they were "greatly concerned" by complaints they had received from a "broad segment of the legal community" that alleged that Smith was insensitive on racial matters and that he displayed "intemperate behavior." Commission members said they planned to monitor his demeanor.

The report did not describe any specific allegations. However, Smith is known around the courthouse for having a short temper, particularly with lawyers who go to court unprepared.

The commission said it had reached its conclusions after conducting an extensive investigation of the allegations, including reviewing transcripts, interviewing participants and meeting with opponents and proponents of his reappointment.

The seven-member commission regularly solicits comments and conducts interviews when a judge seeks reappointment, but in the case of Smith the commission said it had received a "large number" of comments about his tenure.

Smith was automatically reappointed by the commission without further review because four commission members rated him "well qualified," the highest of three possible ratings, while the remaining three members found him "qualified." If the majority had found him "qualified," his appointment would have been sent to President Reagan for review and then to the Senate for confirmation.

Smith was the only Superior Court judge to receive a rating split between qualified and well qualified since the commission began evaluating judges in 1975. Since then the performance of 22 judges has been reviewed; two judges failed to receive automatic reappointment and one judge withdrew. Eighteen judges received ratings of at least well qualified by all seven commission members; until last year judges also could be rated extremely well qualified.

Persons interested in the position should apply to the D.C. judicial nomination commission by Monday.