In December of 2011, BMW and Toyota signed an agreement to collaborate on lithium-ion battery development, and the deal included a provision where BMW would small-displacement diesel engines for Toyota products sold in Europe. It was brought up at the time that the partnership could expand further, and seven months later, it apparently has: Reuters reports the two companies "have now agreed several projects" in "other fields of cooperation."
The Reuters report, based on an article in Germany's Der Spiegel, said there were no more specifics but that the two company CEOS would make an announcement "in the near future." A story in Germany's Manager magazine went further, however, citing the same Der Spiegel piece and saying that BMW and Toyota would form an alliance around "joint projects in hybrid technology, fuel cells, vehicle electronics" and lightweight technology.
The announcement isn't surprising – BMW's move into the small, lightweight hybrid space with its forthcoming i sub-brand gives it all the reason to save R&D dollars by teaming up with the company considered the world's green auto leader, and the rumored expansion topics could help replace BMW's partnership with Peugeot, on the rocks ever since the French firm tied up with General Motors' Opel division. We'll know more when an official announcement is made.