Prime Minister James Marape's government refused to renew the mine's special mining licence in an effort to nationalise the previously successful operation.
Porgera Chamber of Commerce and Industry president Nickson Pakea said those affected included around 700 SMEs and 176 contractors.
"Most of the contractors went through difficult situations when banks recouped vehicles on lease or loan," he told The National newspaper.
Pakea urged the government to provide "relief funding to rescue the business losses".
"The K100 million Business Development Grant declared by the government should be provided as relief funding to the SMEs affected by the mine shut-down," he said.
"We also appeal to the Mineral Resource Enga to sign the shareholding agreement to allow the reopening of the mine as soon as possible."
Pakea said the contractors, mine employees and people in the Porgera Paiela needed assistance.
