OTTAWA - A new federal government study projects that Canada would generate more than $4 billion in long-term GDP gains if it joins the Trans-Pacific Partnership -- but stands to take a $5 billion-plus hit to its economy if it opts out.

The analysis, conducted by the , assesses the potential economic impact of the TPP on Canada and other countries that tentatively signed on to the trade deal last October.

It says if Canada were to ratify the TPP, it would see a $4.3 billion boost to its GDP by 2040, due primarily to the preferential access it would receive to markets in the Asia-Pacific rim.

But the study says if Canada doesn't ratify it while the other 11 member countries do, the country would face estimated GDP losses of $5.3 billion over the same time period.

The report says that's in part because of missed opportunities to enhance trade and an erosion of Canada's preferential market position within NAFTA.

The TPP is the most significant regional trade agreement that Canada has negotiated since NAFTA, which concluded nearly two decades ago.