FRANKFURT, GERMANY — Porsche will provide the first details in mid-September of plans to eventually build a hybrid version of its Cayenne sports/utility vehicle, the company said on May 23, 2005, according to Reuters. Porsche is holding talks with potential partners in the industry to develop a more fuel-efficient derivative of its best-selling model amid rising pump prices and sinking sales of the Cayenne in the United States. "We will not showcase a hybrid study though," a spokesman for Porsche said, referring to the Frankfurt car show that begins in mid-September. North American sales of the Cayenne dropped 27 percent to 4,424 units in the first four months of the year, a decline that Porsche has blamed on a strong base comparison and production bottlenecks, according to Reuters. The spokesman would not name companies with which Porsche is discussing the joint development of a hybrid powertrain, but the Handelsblatt newspaper reported on Monday that it was talking to Volkswagen, DaimlerChrysler and Toyota, citing company sources. Porsche aims to introduce a hybrid Cayenne at the latest when the next generation of its SUV is launched in 2008/2009, the German business daily added. Since the Cayenne is partly assembled in VW's Bratislava plant together with the VW Touareg SUV, Porsche is leaning more towards choosing VW for technological and economic reasons, Handelsblatt reported.