The union representing fast food workers says McDonald's has walked away from negotiations aimed at scrapping controversial zero hour contracts.

It comes after hundreds of fast-food workers took to the streets earlier this month to demand more secure working hours.

NZME says McDonald's, the country's biggest fast-food company with 9000 workers, is now the only major restaurant chain to retain the contracts.

Unite Union national director Mike Treen says the union is "bewildered" by the company walking away from negotiations.