UPDATED 7.01am: An Auckland Council company is being accused of undermining the viability of the rate-paying businesses which help fund it.

The Chamber of Commerce claims Regional Facilities Auckland is creating a monopoly with its exclusive caterers and contractors.

Chief executive Michael Barnett says the council needs to urgently investigate its practices.

He says RFA is using ratepayer funding to subsidise its services, and to charge below market rates which small and medium businesses can't match.

"It's using it's influence in a way that is pushing many small and medium businesses, ratepayers, out of business," he says.

Last year RFA defended its five-year exclusive contract with Ticketmaster, which requires non-sport commercial events to use the ticketing service.

Some event-goers said they were being charged up to 50-percent of the price of their ticket to have it emailed to them.

An RFA spokesman said the contract was secured through a competitive tendering process and the value of the contract was commercially sensitive.

But Michael Barnett isn't impressed.

He says he knows of more than 40 small and medium businesses which can't compete against RFA and its exclusive catering contractor.

Mr Barnett says he would be sad to see those businesses close.

"Their turnover is down by a million dollars. These are guys that are going to have to shut up shop or get out of Auckland."