Noted California divorce lawyer Marvin M. Mitchelson was accused this week of sexual assault by two former clients. Mitchelson is well known for representing such celebrities as Michele Triola, ex-lover of Lee Marvin; Bianca Jagger, ex-wife of Mick Jagger; Connie Stevens, ex-wife of Eddie Fisher; Pamela Mason, ex-wife of James Mason; plus Zsa Zsa Gabor, Carl Sagan, Richard Harris, Tony Curtis, Mel Torme and Stephen Stills.

Mitchelson's two accusers were not named in the police report, but the attorney protested his innocence, declaring that in previous cases they have collectively accused two psychiatrists, a dentist and a minister of sexual assault.

Mitchelson, 58, said he had "spent his career defending women, not attacking them."

District attorney's spokesman Al Albergate said that the sex crimes division of the Los Angeles district attorney's office will most likely decide next week whether to file charges against Mitchelson. Letterman's Dogfight

Late-night TV host David Letterman might have to pay for his ever-so-popular sarcasm. Maryjane Kasian, owner of Randi, a performing poodle that appeared on "Late Night With David Letterman" for the show's weekly feature "Stupid Pet Tricks," is suing the program's host for $1 million, claiming Letterman ruined her dog's show business career.

Speaking on the TV program "Evening Magazine" in July 1983, Letterman said the dog's performance "was a 10" but that the owner had "performed some unethical and intricate spinal surgery on the dog and that's illegal and she'll end up doing time."

A veterinary examination showed that the pet's spine had not been altered, and Kasian's attorney Maria Collias claimed that Kasian's pet grooming business was sharply curtailed and her dog's career suffered irreparable damage after Letterman's comment.

Randi entertained "Late Night" viewers by walking on its hind legs while balancing a glass of water on an upside-down Frisbee. "The dog at the time was an entertainer," Collias said. "He did modeling, he did birthday parties. He was on his way to doing some commercials, and his career was damaged."sk Out and About

It's never too late for former presidents to change their images. Former president Jimmy Carter, with the help of painter Robert Templeton, is no longer modeling blue jeans in the Hall of Presidents at the Smithsonian Institution's National Portrait Gallery. The gallery has replaced its informal Carter portrait by Jamie Wyeth with one by Templeton showing the Georgia president in the Oval Office, clad in a dignified coat and tie . . . John Kennedy Jr. was in Boston Friday to help launch a nationwide search for an artist to design a memorial to President John Kennedy. Even though Kennedy never served in the Massachusetts state government, the memorial will be on the statehouse grounds. "My family is deeply honored by this interest," said Kennedy Jr., who appeared instead of his sister Caroline, now honeymooning with husband Edwin Schlossberg. The memorial is to be unveiled May 29, 1987, the 70th anniversary of the late president's birth . . .

Pepsi-Cola President Roger Enrico is claiming that Michael Jackson caused Coca-Cola Co. to make one of the biggest blunders in modern marketing history. "It's my contention that if Michael Jackson had not moon-walked and spun and flashed his magic glove -- and sung Pepsi lyrics to the tune of his greatest hit on a TV commercial -- the Coca-Cola Co. would not have made the colossal blunder that was New Coke," he writes in an upcoming book. The book, due out in October, has the self-congratulatory title "The Other Guy Blinked: How Pepsi Won the Cola Wars." Enrico also writes about Pepsi's marketing strategy and its series of celebrity ads featuring Don Johnson, Lionel Richie, Geraldine Ferraro, Michael J. Fox and Billy Crystal.