It also said that while it did not plan to do any more work on the national fuel market, it might still take action in some local markets if there was "persuasive evidence of anti-competitive behaviour".

BBC: OFT says UK petrol market is working well

The treatment did not work in three of the patients, and it was also unlikely to work in patients more than three months after diagnosis of diabetes, said Dr Richard Burt of Northwestern.

BBC: Stem cells 'can treat diabetes'

The union, which did not return calls from NPR, will also work with General Motors as it cuts 25, 000 jobs at US assembly and component part plants.

NPR: GM, UAW Make Deal on Benefits