LOS ANGELES, Dec. 16 – The new attorney for Leslie Van Houten, one of three young women defendants in the Sharon Tate murder case, will seek a mistrial for his client after six months of court sessions.

Superior Court Judge Charles H. Older Tuesday ordered the trial to resume Monday after a two-week break occasioned by the mysterious disappearance of Miss Van Houten’s lawyer, Ronald Hughes.

Older appointed Maxwell Keith, a veteran of the Finch-Tregoff trial of a decade ago, to substitute for the missing Hughes. Keith told newsmen Tuesday he intended to ask the court Monday that her case be severed from that of the other defendants — Charles Manson, Susan Atkins and Patricia Krenwinkel—and a mistrial declared for her.

That would mean a complete new trial for Miss Van Houten. She previously has said she does not want a mistrial, does not want Keith to represent her and wants to take the witness stand — but only if she can conduct her own defense.

The jury in the bizarre case has been whiling away the time in locked rooms in the Ambassador Hotel. They have not been in court for two weeks and it appeared they would be sequestered through the Christmas and New Year holidays.

Three floors below the Hall of Justice courtroom, a county grand jury was hearing witnesses in a state bid to indict Manson, 36, for the murder of Donald “Shorty” Shea, a movie stuntman who lived with the “family” at the Spahn Ranch.

Manson already is charged with seven murders in the Tate-LaBianca case arid with the slaying of musician Gary Hinman.

Keith would not disclose what grounds he would present in asking for a mistrial for Miss Van Houten. She is charged only with the two LaBianca slayings.

Hughes, a 250-pound, red-whiskered novice lawyer, not been seen since weekend after Thanksgiving. He reportedly went camping at that time in desolate mountains north of Los Angeles which were swept by torrential rain and winds.

Chief defense lawyer Paul Fitzgerald has said he is convinced Hughes is dead.