en of the 13 scientists who produced a 1998 study linking a childhood vaccine to several cases of autism retracted their conclusion yesterday.

In a statement to be published in the March 6 issue of The Lancet, a British medical journal, the researchers conceded that they did not have enough evidence at the time to tie the measles, mumps and rubella vaccine, known as MMR, to the autism cases. The study has been blamed for a sharp drop in the number of British children being vaccinated and for outbreaks of measles.

"We wish to make it clear that in this paper no causal link was established between MMR vaccine and autism as the data were insufficient," the researchers said in the retraction. "However, the possibility of such a link was raised and consequent events have had major implications."

The study came under fierce criticism last month when the editor of the Lancet said that the lead author of the report, Dr. Andrew Wakefield had failed to reveal that he had a conflict of interest when he conducted the research. At the time, the journal editors said, Dr. Wakefield was also gathering information for lawyers representing parents who suspected their children had developed autism because of the vaccine.

In a statement published on the Lancet's Web site on Feb. 23, Dr. Richard Horton, the journal's editor, wrote: "We regret that aspects of funding for parallel and related work and the existence of ongoing litigation that had been known during clinical evaluation of the children reported in the 1998 Lancet paper were not disclosed to editors."

After the 1998 study appeared, British health officials pleaded with parents to continue vaccinating their children, and a number of other studies were unable to confirm a link between autism and the MMR vaccine.

Dr. Wakefield, who could not be immediately reached for comment, hired a lawyer to demand an apology from the Lancet after the journal released its statement last month, said Dr. Jeff Bradstreet, a colleague.

Dr. Bradstreet, director of the International Child Development Resource Center in Florida, said that Dr. Wakefield had not become involved with the lawyers representing the parents until after the study had essentially been finished. "This has been blown way out of proportion," he said.

In the statement released yesterday, the researchers said that they could not reach one author of the study to ask if he wished to participate in the retraction. Two other authors, including Dr. Wakefield, did not sign the statement, according to the Lancet.