The cost, complexity and accelerated pace of development of self-driving vehicles continue to spark sweeping alliances between automobile manufacturers and suppliers.

In April, rival German automaker Daimler AG formed a similar alliance with supplier Robert Bosch GmbH [ROBG.UL] to speed development of self-driving vehicles.

BMW on Tuesday said it expects that over time there will be "a fairly small number" of self-driving platforms shared by most carmakers because of the tremendous costs of integrating hardware, software and data.

In April, Chinese internet search firm Baidu Inc said it would make its new Apollo self-driving platform available to other companies.

On Monday, Alphabet Inc's Waymo self-driving unit and ride services startup Lyft Inc announced a self-driving vehicle partnership. Waymo has been shopping its self-driving platform to global automakers and has modest deals with Fiat Chrysler Automobiles NV and Honda Motor Co Ltd.

Delphi will share with the BMW alliance some of the work it has been doing on a separate self-driving platform it is developing with Intel and Mobileye NV, the Israeli vision system and mapping expert that is being acquired by Intel, said Glen De Vos, Delphi's chief technology officer.

Delphi also may provide radar and other sensors to the BMW self-driving platform, which is targeted for production in 2021.

BMW, Daimler and Intel jointly own Here, a high-definition mapping service, along with Volkswagen AG and Tencent Holdings Ltd, the Chinese internet giant. Here is positioning itself to be a key supplier of maps for self-driving cars.