Businesses involved in pricefixing, market-sharing, bidrigging or other cartels can wipe the slate clean and escape punishment if they own up to the scam, The Office of Fair Trading has said.
Research by the organisation suggests that a quarter of SMEs in the UK feel they have been a victim of anticompetitive practices and a third are aware of such practices in their own industry.
With the launch of Come Clean on Cartels Month today, OFT hopes to highlight the benefits of its leniency programme to small and medium-sized business.
Under the programme, firms can blow the whistle on a cartel they may be involved in and receive partial or even total immunity from fines.
Philip Collins, OFT chairman, said: "We want to urge businesses, especially SMEs, to make a clean break with any anti-competitive agreements they may be involved in.
"Such activities are illegal, and can result in a fine of up to ten per cent of turnover of a business, or even a prison sentence.
"SMEs form the dominant part of the economy and we want to ensure that they operate in competitive markets."