French President Valery Giscard d'Estaing today told a group of ralatives of the U.S. hostages in Tehran that the length of their captivity, "far from leading to resignation, makes it that much more intolerable."

The French leader apparently went out of his way to receive four representatives of the Family Liaison Action Group at the start of their tour of West European capitals to rally allied support.

The four women in the group expressed pleased surprise at being received so quickly by Giscard after arriving today. He saw them for about 45 minutes this afternoon while a group of French mayors who had been scheduled to see him waited.

"It was a wonderful, wonderful meeting," said the families' spokeswoman, Louisa Kennedy of Washington. "We all felt very uplifted. He was extremely sincere, very supportive, very concerned and genuine."

French officials also went out of their way to see that the U.S. media got accounts of the meeting at the Elysee Palace. French officials have been upset that the American press has been depicting France as hanging back on the hostages issue when it has been among the most active behind the scenes to back up U.S. efforts to free the hostages, they say.

Kennedy, whose husband, Moorhead, was an economic and commercial attache at the Tehran embassy, said that Giscard told them the hostage situation has reached the point that the West Europeans needed to do something more.

Yesterday, the nine member states of the European Community agreed in a foreign ministers' meeting in Luxembourg to reduce their embassy staffs in Tehran and to apply economic sanctions against Iran if the hostages are not released by mid-May, when a new Iranian parliament is scheduled to meet and deal with the issue.

Kennedy said that the group agreed that much of what Giscard told them was confidential and ought not to be discussed publicly. He appears to have explained in detail the Luxembourg decisions.

An Elysee spokesman said Giscard "expressed to the relatives of the hostages the deep sympathy and solidarity of france, the country of the rights of man, for the hostages."