The European Economic Community has told the Carter administration that the new multilateral trade agreement is jeopardized by text changes made in the U.S. Senate.

The nine-country group voiced concern over what it call Senate attempts to "welsh" on a key trade concession made by the United States during the protracted "Tokyo round" of negotiations to reduce tariffs and stimulate trade among non-Communist nations.

EEC trade negotiator Wilhelm Haferkamp, in a letter to Robert Strauss, President Carter's special trade representative, indicated that the Nine would not ratify the new accord without prior guarantees' that Congress would approve the full text of the document initialed at Geneva earlier this month.

The concession in question involves the U.S. acceptance of the so-called "material injury" clause that would require American companies to show they had suffered significant commercial damage from subsidized foreign imports before countervailing duties could be used to retaliate agianst the foreign country

The Senate Finance Committee, which is now considering the trade package, has eliminated the word "material" from the initialed text. This in turn has prompted European fears that Washington would soon resume arbitrary impositions of penalty duties on certain foreign imports. The duties now are temporarily suspended by executive waiver authority.

The Europeans, in effect, reminded the Carter administration that the accord is a dead duck if congressional actions produce any deviations on key issues contained in the negotiated text.