President Clinton has suspended for another six months a provision in the 1996 Helms-Burton Act that lets U.S. firms sue companies dealing in properties seized after Cuban President Fidel Castro took power in 1959.

He notified Congress of the six-month extension in a letter to the chairmen of relevant committees in the Senate and House. The letter was sent Friday and released yesterday.

Clinton has regularly used his authority to suspend the right of U.S. companies to sue, seeking to avoid angering European countries and Canada. They have sharply condemned the lawsuit provision as an example of the excessive reach of U.S. power.

"This action is taken in the national interest and because it is the best way to secure the act's objective of promoting a transition to democracy in Cuba," White House spokesman Joe Lockhart said in a statement.

Sen. Jesse Helms (R-N.C.), co-sponsor of the 1996 legislation, has criticized the suspensions as an unjustifiable weakening of the law.

Lockhart defended the waiver, saying the international community's pro-democracy message to the Cuban government has been "stronger and clearer than ever."

"Leaders from around the world have pressed, both publicly and privately, senior Cuban officials on the need for human rights and democratic change," he said.

Lockhart said the Clinton administration has pledged to "encourage and work with our allies and partners on effective steps to hasten the day when Cuba will join the community of democratic nations."