OTTAWA — Canada is working with the European Union to revise controversial investor protection provisions in their landmark free trade deal at the direction of the new Liberal government.

But Canada's chief negotiator Steve Verhuel says the ongoing work with the EU does not mean that pact has been reopened to negotiation.

The comprehensive pact in goods and services, known as CETA, has been plagued with delays since negotiations publicly ended in the summer of 2014 after what was then five years of talks.

Verhuel says the Europeans first raised the question of revisions after political opposition arose in Europe in 2014 over the chapter that deals with settling disputes between companies and governments, known as ISDS.

The Trudeau government wants to see if improvements can be made in the ISDS chapter to make the dispute resolution mechanism more favourable to Canada, Verhuel says.

He says he expects the deal to be ratified by both sides and fully implemented in 2017.