LOS ANGELES, Jan. 11 – The oft-delayed Sharon Tate murder trial hit a new snag today when the critical illness of the daughter of a defense attorney caused him to delay his final argument.

Maxwell Keith, who replaced the missing Ronald Hughes as counsel for Leslie Van Houten, said his daughter’s surgery during the weekend had so concerned him that he had been unable to prepare his final argument.

The judge considered a defense motion presented by attorney Paul Fitzgerald to declare a mistrial on grounds that there had not been a public trial, due to the fact that the majority of the courtroom seats were reserved for the news media.

The trial was expected to wind up by midweek despite the brief delay. Keith indicated he expected to begin his summation tomorrow.

It will be the first time Keith has spoken to the jurors, who heard Hughes defend Miss Van Houten, 21. Hughes disappeared during a Thanksgiving weekend camping trip.

Miss Van Houten is charged with murder-conspiracy along with Charles Manson, 36, and two other women members of his hippie clan. Miss Tate and six others were killed in August 1969.

Keith’s argument will be followed by a prosecution summation.

Prosecutor Vincent Bugliosi, who argued for four days before the defense took over, says he’ll rebut for at least two days.

Since the trial began the jurors have been kept under close watch in a Los Angeles hotel.

Yesterday they visited the Palm Springs Aerial Tramway, ascending snow-covered Mt. San Jacinto about 90 miles east of Los Angeles. Sheriff’s deputies with them asked onlookers not to speak to the jurors.

It was not the jury’s first weekend outing, officials said, but it was the first whose location was discussed.