The competition watchdog has delayed its decision on BP's $1.8 billion acquisition of more than 500 service stations owned by Woolworths.
The Australian Competition and Consumer Commission said on Wednesday that it needed more time for "data analysis, and to consider information provided by parties and market participants."
It was due to deliver its ruling on the deal on October 26, but that has now been pushed back to November 30.
In August, the ACCC said it was concerned that motorists could end up paying more for fuel if the takeover went ahead.
ACCC chairman Rod Sims said at the time that the deal could substantially reduce competition in metropolitan areas by reducing the number of rivals in the fuel market.
Woolworths agreed in December 2016 to sell its 527 petrol stations and 16 development sites to BP, which already owns 350 retail sites in Australia and supplies a further 1,050 BP-branded sites.
If the deal gets the green light, BP and Woolworths plan to jointly roll out up to 200 new format convenience stores, rivalling Caltex and Shell-owner Viva Energy in the fuel convenience store market.
BP has also previously said it plans to keep the Woolworths four cent per litre discount offer.
The acquisition also requires approval from the Foreign Investment Review Board.
Shares in Woolworths were down 48 cents, or 1.9 per cent, at $24.52 at 1450 AEDT, in a weak market.
