Complex sentence: Quebec laws effectively made it nearly impossible for Ontario-owned construction companies and Ontario-trained tradespeople to work in Quebec; the Act retaliated by placing similar restrictions on Quebec-trained tradespeople and Quebec-based companies seeking work in Ontario.
Split into simpler sentences: Quebec laws effectively made it nearly impossible for Ontario-owned construction companies and Ontario-trained tradespeople to work in Quebec. The Act retaliated by placing similar restrictions on Quebec-trained tradespeople and Quebec-based companies seeking work in Ontario.