ISE Corp., Siemens Venture Capital, Macquarie Clean Technology Fund and DTE Energy Ventures Inc. announced the completion of a $17.5 million equity investment in ISE, a supplier of advanced hybrid-electric drive systems and components for heavy-duty vehicles.

The funds will be used to continue ISE's rapidly growing sales to the transit bus marketplace in the

and

and the expansion of the company's prominent energy storage systems. The Series D preferred stock financing also includes additional investments from RockPort Capital Partners and NGP Energy Technology Partners, investors in ISE's previous Series C and Series B preferred stock financings.

ISE specializes in the production of "series" hybrid systems, where the combustion engine is completely decoupled from the driveline and used only to generate electrical power, thereby allowing the engine to operate in a smoother and more efficient mode. The company combines its proprietary control systems, advanced energy storage systems and electrically-driven accessories with electric motors, motor controllers, generators and other high quality components that it develops internally or purchases from industry leading suppliers, such as Siemens.