A deal to stop supermarkets using restrictive leases to stifle competition is meaningless on its own, a leading consumer advocate says.

The Australian Competition and Consumer Commission yesterday announced secondary supermarket players Metcash (which supplies IGA stores), Foodworks, SPAR, Franklins and Aldi had agreed they would not enter into any new leasing arrangement which includes restrictions on competition, and would not enforce any such provisions in existing leases beyond five years of trading.

It follows a similar deal with majors Coles and Woolworths last year.

ACCC chairman Graeme Samuel said the latest deal meant "many more shopping centres will no longer be hamstrung by restrictive provisions in leases that prevent or hinder the entry of competing supermarkets".

Federal competition policy and consumer affairs minister Craig Emerson said it would lead to shoppers having more choice.

"Competition is the best way to keep prices down and by agreeing to end these restrictive conditions in their leases, competition is boosted which is great news for shoppers," Dr Emerson said.

"I am heartened by this development because consumers will be the winners when we have several supermarkets operating in the same precinct."

But competition expert Frank Zumbo, of the University of NSW, said the reforms, like the Coles and Woolworths announcement, were "meaningless".

"The simple reality is that consumers can't switch to another supermarket if that other supermarket is not allowed to open up in the shopping centre," he said.

"Removing restrictive clauses will do nothing for competition if new supermarket competitors can't get into existing shopping centres."

The Coles and Woolworths deal was for 80 per cent of restrictive leases to be removed, with the remainder to be phased out.

"Until all restrictive lease clauses are removed and until additional supermarket competitors are allowed to open up in shopping centres around the country, the federal government will only be fiddling around the edges and failing to tackle the underlying problem in the Australian supermarket sector and that's the dominance of Coles and Woolworths," Mr Zumbo said.