Families of the American hostages in Tehran have expressed objections to the Carter administration's effort to arrange for medical treatment for the deposed shah of Iran.

The objections were raised in a letter delivered to the White House Saturday afternoon, according to a representative of a group recently formed by members of the hostages' families.The letter was endorsed by 47 of the families, the representative said.

"It was our feeling that the administration should not be negotiating with the shah," said Louisa Kennedy, speaking for FLAG (Family Lialson Action Group). Kennedy's husband, economic and commercial officer Moorhead C. Kennedy Jr., is a hostage. "We were in a certain despair about the fact that the administration seems to take on the shah's problems."

Louis Kennedy declined to make public the text of the letter, saying it was intended to be private and "not meant to put the president on the spot." The letter was prompted, in part, by the negotiations in Panama last week of White House chief of staff Hamilton Jordan and other U.S. officials, who were seeking to arrange medical treatment for Shah Mohammad Reza Pahlavi. Kennedy said the group had no immediate comment on reports that the shah was on his way to Egypt.

Fifty Americans are being held hostage at the U.S. Embassy compound in Tehran and three others are confined at the Iranian foreign ministry, according to the U.S. State Department. Kennedy said that two families declined to endorse the letter to President Carter and four others could not be reached.

The letter also expressed concern about the possibility that the shah might undergo medical treatment either in the United States or in a U.S. medical facility abroad.