BMW AG says it will supply more than 240,000 3.0L diesel engines to upstart Carbon Motors Corp. for its upcoming purpose-built police car.

The deal, signed today in Washington by BMW sales chief Ian Robertson and Carbon CEO William Santana Li, calls for BMW to deliver its inline 6-cyl. diesel, coupled with an automatic transmission, to Carbon in time for the 2012 production launch of its E7 police car.

The two companies do not indicate the length of the supply deal, reportedly valued at more than E1 billion ($1.4 billion).

BMW currently offers its 3.0L, twin-turbo diesel in the U.S. in its X5 cross/utility vehicles and 3-series sedan, where output ranges at 265 hp and 425 lb.-ft. (580 Nm) of torque. The diesel is built at a plant in Steyr, Austria.

But a BMW spokesman says Carbon’s E7 is more likely to use the twin-scroll, single-turbo 6-cyl. diesel currently offered in Europe in the 5- and 7-Series sedans.

Carbon previously said its E7 turbodiesel would deliver 250 hp and 400 lb.-ft. (542 Nm) of torque, without revealing the source of the engine. The 6-speed automatic Carbon will get is expected to be the 6HP26 TU unit used in the 750i.

Last year, BMW sold about 498,000 diesel-equipped vehicles worldwide, accounting for about 39% of its total deliveries. Diesels accounted for 17% of X5 sales in the U.S. in 2009, the auto maker says.