The international credit ratings agency said that the foray into petrol retailing involved significant risk, which would be compounded if the venture was funded by bank debt.
The retailer is hoping to attract more customers to its chain by offering discounts of a few cents per litre if purchases exceed a certain threshold. At Woolworths that threshold is $30 per store visit.
On the upside Coles Myer chief executive John Fletcher has predicted that the move into the discount petrol sector will generate up to $1billion in revenue annually.
Woolworths, which already has fuel outlets across Australia, is also reportedly considering offering a 10c-per-litre discount to encourage customer loyalty in anticipation of the entry of Coles Myer into the petrol retailing industry.
