Factbox: Details of the new North America free trade deal

(Reuters) - The United States and Canada forged a last-gasp deal on Sunday to salvage a three-country, $1.2 trillion open-trade zone agreement with Mexico that had been about to collapse after nearly a quarter century.

Here are some of the details in the agreement, which will change its name from NAFTA to the United States-Mexico-Canada Agreement (USMCA) and must be ratified by each country's legislature before it takes effect:

RETAIL

The deal would raise Canada's minimum duty-free shipment threshold, but by less than the United States had wanted, a relief for Canadian retailers facing competition from online stores based in the United States. Canadian residents buying from U.S. retailers will not pay duty on purchases below C$150 and will not pay Canadian sales tax on purchases under C$40, according to the draft text. Mexico had agreed to a single $100 threshold.

PHARMACEUTICALS

The deal sets a 10-year period of protection for biologic drugs, a class that includes many of the world’s top-selling drugs like rheumatoid arthritis treatment Humira and cancer drug Avastin. That means Canadian patients will have to wait longer for cheaper generic alternatives, called biosimilars, to hit the market.

Canada previously had an eight-year period of protection for those drugs, according to University of Ottawa law professor Michael Geist. He said the longer period would likely result in higher drug prices and higher healthcare costs in Canada.

WHEAT GRADING

Canada and the United States agreed that wheat imported from the other country would not be treated less favorably than similar domestic wheat. U.S. farmers have complained that their wheat automatically receives the lowest price under Canada's grading system.

DAIRY

Canada agreed to provide U.S. dairy farmers access to about 3.5 percent of its approximately $16 billion annual domestic dairy market, Canadian sources said, adding that the Canadian government was prepared to offer compensation to dairy farmers hurt by the deal.

Under the agreement, Canada has agreed to eliminate its Class 6 and Class 7 milk categories and associated pricing schedules for skim milk, skim milk proteins and other components and ultrafiltered milk, within six months after the USMCA goes into force.

U.S. farmers said those schedules had effectively pushed them out of the Canadian dairy market.

The agreement will increase U.S. access to Canada's dairy market beyond Trans-Pacific Partnership levels, a senior Trump administration official said.

CHICKEN AND EGGS

The United States gets tariff-free access to Canada for 57,000 tonnes of chicken by year six of the deal, growing 1 percent for an additional 10 years.