Doctors have separated severely deformed year-old Siamese twin boys whose parents were accused of trying to starve them, hospital officials said today.

The parents, Dr. Robert Mueller and Pamela Schopp of Danville, Ill., allegedly had asked that food be withheld shortly after birth so the twins would die. A caseworker later said the twins were "well cared for and loved."

A spokesman at Children's Memorial Hospital said Jeff and Scott Mueller were in critical but stable condition. They underwent nine hours of surgery Thursday, The Chicago Sun-Times reported.

No other information was released at the request of the parents, who had been charged with attempted murder for allegedly asking that food be withheld from the twins after their birth at Danville's Lakeview Medical Center May 5, 1981.

Those charges were dismissed in July, 1981, and a grand jury refused to return indictments against the couple and their family doctor earlier this year.

Doctors at Children's Memorial, where the twins were transferred eight days after their birth and were treated until last September, initially said both infants could not survive surgery to separate them.

That type of surgery on twins who share vital organs and neural and vascular systems is rare, doctors said.

But Juvenile Court Judge John P. Meyer, who returned full custody to the parents this year, ordered another evaluation.

He also ordered court-appointed attorneys for the boys to continue representation.

In Danville today, Frederick Underhill, who represents Jeff, said he gave permission for the surgery after he examined medical reports and discussed the case with doctors.

Jerry Davis, the attorney who represents Scott, said his decision to approve the surgery was made "after extensive review of the proposal."

State caseworkers praised the care the twins received from their parents after they were released from Children's Memorial and went to their Danville home to live last September.

In one report, caseworker Jan Miller told the court the twins had been "extremely well cared for and loved." Medical reports have indicated that Jeff is the stronger and that Scott has suffered from chronic heart problems.

At a neglect hearing in Danville more than a year ago, Dr. Carl Hunt, director of newborn intensive care at Children's Memorial, said they were joined in the mid-abdomen region and "one kind of merged into the other."

"From the waist up, both twins looked fully developed," he said.

The twins each had one normal leg and shared a fused leg, he said. They also shared the large intestine and each had one kidney, he reported.

Siamese twins are born once in every 500,000 to 600,000 births, and the type in this case represents about 6 to 7 percent of all Siamese twins. At the time, Hunt said he knew of only one case in which that type of twins was successfully separated, and those were girls.