Five Harvard Medical School teaching hospitals released a joint statement Friday publicly confirming reports that they have been discussing ways to cooperate more closely.

The statement, signed by the chief executive officers and the chairs of the boards of Beth Israel, Brigham and Women's, Children's, Mass. General and New England Deaconess hospitals, said the board chairs "have agreed to oversee a six-month planning study to analyze and make recommendations." Medical School Dean Daniel C. Tosteson '44, who initiated the discussion of cooperation, also signed the letter.

Sources said the structure of the review is yet to be defined, but will likely include study groups that will study various aspects of proposed collaboration between the hospitals, which have traditionally been fiercely independent competitors.

"With our leadership responsibilities in patient care, research and education, our institutions have a special obligation to the community to maintain and improve the quality of what we do, while significantly reducing our costs. We believe that this will not be possible in the coming years without closer coordination," the statement said.

A Washington-based anti-trust lawyer has been attending the talks, which were convened by Harvard Medical School in what the statement said was a "response to the significant, far-reaching changes taking place in health care."

The statement said, "The possibility of closer coordination presents a challenge and an opportunity for all of us. While the outcome remains unknown, we firmly believe that new ways of thinking about how we carry out our mission will be required for us to flourish in the coming years."

Those familiar with the discussions said they are still at a "very preliminary" stage. But even with the outcome unknown, the news of the discussions between c.e.o.'s has ignit- ed considerable discussion--and some strong concerns--among hospital employees.

In two dozen interviews on Friday, employees at four of the five hospitals who had heard of the discussions seemed to conceive of the talks as a pathway to a merger into a "mega-hospital." In fact, while increased cooperation is a likely outcome of the talks, those familiar with the discussions between the hospitals and with the Boston health care scene say the creation of a 3000 bed hospital is unlikely.

"I don't think there'll ever be a complete merger," Stephen B. Kay '56, vice chair of the board of trustees of Beth Israel Hospital, said last week.

While employees may be misinformed about the exact nature of the talks, about three quarters of those interviewed had at least some idea that conversations were going on between the hospitals.

Many of those who had heard said they worry that the cost-cutting and new efficiencies billed as a benefit of cooperation might mean the loss of their jobs.

"I think it's bad," said Sergio Medrano, a biomedical technician at Brigham and Women's Hospital. "When these hospitals merge with the other hospitals, the one with more power ends up staying the same and the others have layoffs."

Rodrigo Lozano, also a biomedical technician at Brigham and Women's, said he expects layoffs.

"There's probably going to be some layoffs. I'm afraid they'll choose me," Lozano said.

Lozano said the biomedical technicians from all five hospitals could be consolidated into one operation, and that made him fearful. "That's probably one area they could centralize. There could definitely be less people if they consolidated," he said.

Janice Burnette, who coordinates research in the cardiology department of Children's Hospital, said, "I think it's going to be something that's very painful. That means a lot of jobs lost."