An advertisement by a Shepparton car dealer may have misled consumers by falsely giving the impression it had a bulk deal in respect of certain vehicle models.

The Australian Competition and Consumer Commission has accepted a court enforceable undertaking from Thompsons of Shepparton Pty Ltd trading as Thompson Motor Group and its director, Mr Jarrod Thompson.

The undertaking was provided to the ACCC after concerns were raised about the content of some of Thompson's advertisements aired on the Prime television network in regional northern Victoria and southern New South Wales in late 2007.

The advertisements show large numbers of new Nissan, Kia and Holden motor vehicles parked in an allotment with the following voiceover by its director Mr Thompson:

"Here at Thompson Motor Group we have just secured a bulk deal direct from the manufacturers. This exclusive offer is on all Navaras, Patrols, Commodores and Astras. I personally secured this deal and I guarantee it will save you money."

"The advertisement may have led consumers to believe that Thompsons had purchased large numbers of vehicles for a discounted price which would allow savings to be passed on to them," ACCC Chairman, Mr Graeme Samuel, said.

"However, Thompsons had not purchased any Holden Commodore sedans or Holden Astras as part of the bulk deal referred to in the advertisement."

Mr Samuel said the ACCC was concerned that the representation by Thompsons may have contravened sections 52 and 53(e) of the Trade Practices Act 1974.

These provisions prohibit misleading and deceptive conduct or conduct that is likely to mislead or deceive as well as false or misleading representations as to the price of goods or services.

In response to concerns by the ACCC, Thompsons and its director, Mr Thompson, have offered a section 87B undertaking to the ACCC.

As part of the undertakings, Thompsons will implement and maintain a trade practices law compliance program for three years and three months from the commencement of the undertaking.

A copy of the undertaking will be available on the ACCC's website under Public Registers.