The Chinese government and Norway signed a new salmon protocol Monday allowing Norwegian salmon farmers SalMar, Leroy, and Nordlaks to resume exports to China from some processing plants after a four-year halt.

Leroy’s Aurora plant, SalMar’s Innovmar site, and Nordlaks’ only processing plant, located in Stokmarknes, will resume exports to China immediately.

“It is very gratifying news. The last three processing plants are now opened up for China,” said Harald Tom Nesvik, minister of fisheries of Norway.

The three processing plants were banned from exporting to China in March 2015 due to alleged findings of pancreas disease (PD) virus in the salmon.