The next potential Canada-U.S. trade dispute unfolded Thursday as aerospace giants clashed at a Washington hearing that marked the formal launch of investigations into Boeing's allegations that Bombardier received subsidies allowing it to sell its CSeries planes at below-market prices.

"The U.S. market is the most open in the world, but we must take action if our rules are being broken," U.S. Commerce Secretary Wilbur Ross said in a statement after the hearing began.

"While assuring the case is decided strictly on a full and fair assessment of the facts, we will do everything in our power to stand up for American companies and their workers."

This was excerpted from the 18 May 2017 edition of CBC News.