Following the forced resignation of its transplant chief, the University of Pittsburgh Medical Center announced the appointment of an interim chief yesterday and said a search was under way for a permanent successor.

Dr. J. Wallis Marsh Jr., a transplant surgeon who has been with the university 15 years, was named interim chief of the transplant division of the UPMC Thomas E. Starzl Transplantation Institute.

He will temporarily fill a vacancy created this month when Dr. Amadeo Marcos stepped down as transplant chief. Dr. Marcos had been asked by UPMC to resign after violating the system's code-of-conduct policy.

A search for a permanent successor "is ongoing," said system spokeswoman Maureen McGaffin.

As interim chief, Dr. Marsh, 53, will oversee day-to-day operations of the division. He is a professor of surgery at the Pitt School of Medicine and co-director of the UPMC Liver Cancer Center.

"Dr. Marsh brings a wealth of experience to this position, including performing more than 500 liver transplants," said Dr. Timothy Billiar, the medical school's chairman of surgery. "Additionally, his skills as a scholar in academic medicine will help bolster the mission of the Starzl Institute by fostering the continual improvement of the clinical, scientific and social aspects of transplantation."

Dr. Starzl characterized the move as "a good step" and called Dr. Marsh "a very fine surgeon."

An Arkansas native, Dr. Marsh received undergraduate and medical degrees from the University of Arkansas. He completed a general surgical residency at St. Paul Hospital in Dallas and a surgical fellowship in kidney transplantation at the Mayo Clinic. He joined the Pitt School of Medicine as an assistant professor of surgery in 1985 and completed a one-year fellowship in liver transplantation under Dr. Starzl's direction.

In 1989, Dr. Marsh joined the faculty of the Washington University School of Medicine in St. Louis. He returned to Pitt in 1993.

In 2001, he received a master of business administration degree from Pitt. His areas of research include improving outcomes for transplant patients with liver cancer and computer technologies.

Dr. Marsh surfaced in news accounts following the 1998 death of country singer Tammy Wynette. They indicate that he treated her in St. Louis and that she also had treatment at UPMC. Her family sued Dr. Marsh, alleging he mismanaged her case. The matter was later settled out of court.