Belgian Foreign Minister Didier Reynders signed the accord on behalf of this country in the presence of EU Trade Commissioner Cecilia Malmstrom and Canada's ambassador to Belgium.

"Nothing is easy in Belgium, but few things are impossible," Reynders tweeted after the signing.

The European Union and Canada will formally sign the landmark free trade deal in Brussels on Sunday after a series of key votes in Belgian regional assemblies on Friday ended opposition that had threatened to destroy the entire agreement.

Moments after the final Belgian vote, European Council President Donald Tusk called Canadian Prime Minister Justin Trudeau and invited him to Brussels for the signing ceremony, which is scheduled for 12 p.m. (1000 UTC). 

Supporters of the the Comprehensive Economic and Trade Agreement (CETA), claim the pact will boost bilateral trade by 20 percent. All 28 EU governments back CETA but Belgium's central government had been prevented from giving consent because it needed approval from sub-federal authorities in French-speaking Wallonia.

Controversial deal

CETA is controversial in both Europe and Canada. Thousands have marched in recent months arguing that its system of harmonizing regulations could allow transnational corporations to undercut laws that protect the environment, public health and worker safety.

Wallonia's prime minister, Paul Magnette, had become a hero to protesters across Europe when he and his Socialist regional parliament withheld their support. But on Saturday, he said amendments that safeguard farmers had produced something Walloons could live with. 

"The amended and corrected CETA is more just than the old CETA. It offers more guarantees and it is what I will defend," Magnette said.

Not everyone in Wallonia agreed.

"It is clear that the text of CETA stays the same: the DNA of CETA is one of deregulation and it puts nations in competition at an unprecedented level," said Frederic Gillot of PTB-GO, a leftist party that often competes for votes with the Socialists.

Opposition to CETA is part of a growing backlash in the West against neo-liberalist policies that critics say favor international investors over national interests. CETA is similar to the EU-US deal known as TTIP which is also expected to be a tough sell on both sides of the Atlantic.

jar,nm/sms (Reuters, dpa)