According to The Scotsman newspaper, Finnie said it was important that Scotland's food and drink industry made its views known to the Competition Commission, which is carrying out an inquiry into the£95 billion grocery retail market.
The investigation into the big four - Asda, Tesco, Sainsbury's and Morrisons - is the third in seven years, but previous inquiries have failed to establish misconduct because of insufficient evidence.
Yesterday, Finnie met Competition Commission chairman Peter Freeman, who has been in Scotland for two days gathering evidence for the inquiry.
In his submission to the commission, Finnie highlighted allegations that food producers were being forced to enter unsustainable Bogof (buy one get one free) promotions.
Freeman added that those submitting evidence should have nothing to fear. 'We're used to carrying out this sort of investigation and we can assure that no one will be identified who doesn't want to be,' he said.
Supermarkets will know by Christmas if they are likely to face Government intervention.