The House of Commons on Saturday approved the Canada-U.S. free-trade agreement as opposition lawmakers sang the country's national anthem to protest what they said was a sellout of Canada's sovereignty.

The sweeping legislation will begin breaking down trade and business barriers with the United States as early as New Year's Day."People will look back on this and say it was a good day for Canada," said Prime Minister Brian Mulroney. He said the agreement, which was approved by a vote of 141-111, would bring economic prosperity.

In Washington, a U.S. administration trade official welcomed the Commons vote, saying the trade pact would spur economic growth on both sides of the border.

"We're just very pleased the Canadian Parliament has acted positively on the free-trade agreement," said Kelly Winkler, spokesman for Trade Representative Clayton Yeutter.

The agreement was the focus of national elections Nov. 21, in which Mulroney's Progessive Conservative Party won a second consecutive majority government.

"It was a tough road; this is a rough business," Mulroney told reporters outside the Commons, which had met past midnight.

Legislators of the opposition Liberal Party sang "O Canada," the Canadian national anthem, to protest passage of the bill. Members of another opposition group, the New Democrats, were silent as they voted against it.

The pact is scheduled to take effect Jan. 1 after consideration by the Senate, which has promised to approve the legislation next week.

Under the agreement, all remaining tariffs between the two neighbors are to be phased out over a 10-year period. Trade between the United States and Canada was about $160 billion last year.

The opposition bitterly opposed the pact on the ground that it would cost Canadians jobs. After the election, the Commons was recalled Dec. 12 to deal with the agreement.

Mulroney signed the trade agreement with President Reagan in January. It was approved by the U.S. Congress.