The consumer watchdog may seek heavier fines for companies that breach consumer laws after criticism of penalties handed out to Coles supermarkets for illegally squeezing suppliers.

Australian Competition and Consumer Commission chairman, Rod Sims, will use a speech in Sydney on Thursday to push for penalties that provide appropriate deterrence to companies that breach consumer and competition laws.

“Some companies think they have a lot to gain from breaching our competition and consumer law – they should have much to lose as well,” Sims said, before outlining the ACCC’s priorities for 2015 in a speech to a Committee For Economic Development of Australia lunch.

Sims said the initiative followed commentary that an $11 million penalty handed to Flight Centre for attempting anti-competitive conduct, and an $11.25 million charge to Coles for unconscionable conduct towards suppliers, were inadequate.

Online retailers and other web-based businesses will receive renewed attention from the commission, with Sims listing delays by online business in addressing consumer complaints as an area of concern.

The ACCC will also focus on cartel conduct in government procurement, truth in advertising and consumer issues in the health sector as priorities this year, Sims said.

AAP