FRANKFURT, Oct 19 (Reuters) - Private equity company Bridgepoint Group has agreed to buy a majority stake in traffic and transport software maker PTV Group from parent Porsche SE for an undisclosed sum. Porsche SE, the largest shareholder in Volkswagen , said it would keep a 40% stake in the unit, whose software is being used by more than 2,500 cities and municipalities worldwide. In the last financial year PTV’s operating profit stood at 5.3 million euros ($6.2 million) on sales of 108 million euros. It employs roughly 900 staff. “With Bridgepoint and their buy-and-build expertise, we have now found the right partner to lead PTV together with the management team ... into a very successful future,” Porsche SE board member Lutz Meschke said. $1 = 0.8581 euros Reporting by Christoph Steitz and Ilona Wissenbach; Editing by Jan Harvey