The German company is worried about falling profits as the global credit crunch adds to rising oil and raw materials costs.
One plan being looked at is for the Mini to share a vehicle platform with the BMW 1-series in the future.
According to the German trade magazine Automobilewoche, this might happen if plans to jointly develop a small car platform with Fiat fall through.
The magazine says BMW chief Norbert Reithofer has called for a sharp reduction in Mini production costs at Oxford even though demand globally is buoyant and the factory is running to capacity.
Last week the Oxford plant finished production of the popular Mini Convertible which still uses the first Mini platform. The assembly lines will now run at full capacity to meet demand for the second generation Mini and Clubman model.
The company said a new convertible is being developed for the second generation Mini, but the launch date is yet to be revealed.
BMW has not said what other measures it might take at the Mini plant as analysts predict the company's profits are expected to fall by 40% this year.
Automobilewoche said Reithofer has already halted development of a rumoured luxury SUV, called the X7, while the company wants to reduce labour costs by outsourcing operations such as its fleet-driver service, security and food-services.