He said that with manufacturing in Northern Ireland still in "big trouble", it is "ridiculous" that firms could face higher gas and electric costs.
"I believe some businesses may close because of this. Most businesses are operating at breakeven point or below breakeven in this sector and this is going to have a devastating effect on some of them," Mr Cullen added.
With the Irish Times reporting last week that businesses can save up to ten per cent on their bills by switching energy provider, this could be a life-saving option for many firms.
The newspaper suggested changing provider as a "genuinely easy" was of reducing expenditure during the recession.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.