Apple CEO Tim Cook went to BMW's headquarters in 2014, and senior Apple executives toured the carmaker's Leipzig factory to learn how it manufactures the i3 electric car, sources familiar with the matter told Reuters.
The dialogue ended without conclusion because Apple, the world's largest maker of electronic gadgets, appears to want to explore developing a passenger car on its own, one of the sources said.
Also, BMW, the world's biggest seller of premium cars, is being cautious about sharing its manufacturing know-how because it wants to avoid becoming a mere supplier to a software or Internet giant.
But one of the sources said the exploratory talks between senior managers might be revived.
Reuters contributed to this report