The chairman of a House transportation panel said President Clinton's successful mediation effort to end the American Airlines attendants' walkout

underscores the need for enactment of striker replacement legislation next year.

In a letter to the president, Rep. Norman Mineta, D-Calif., chairman of the House Public Works and Transportation Committee, urged Mr. Clinton to push for Senate passage of legislation prohibiting employers from permanently replacing workers who strike over economic issues.The House easily passed the bill in June, but Senate supporters lacked the 60 votes needed to cut off debate and end a filibuster against the bill.

Rep. Mineta said the president should use the same strong approach he employed to gain support for the North American Free Trade Agreement to turn around the few votes needed in the Senate to pass striker replacement legislation.

A labor lobbyist said unions are still two to four votes short.

''We would just hope that President Clinton would work as actively on this as he did at getting Nafta through," the lobbyist said.

Without the legislation, "every strike will become a life-or-death struggle for the strikers, since anything less than complete victory will result in the destruction of their careers," and the White House "will become the focus of all labor-management conflicts," said Rep. Mineta.

"American's ability to hire permanent replacements escalated the dispute, by making American less willing to negotiate and compromise, on the assumption that the threat of permanent replacements would prevent the employees from mounting a successful strike," he added.