BERLIN—Top Volkswagen shareholder Porsche SE supports plans to list luxury sportscar maker Porsche AG but the conflict in Ukraine could affect the timing of the proposed IPO, the holding company said on Tuesday. Volkswagen aims to conduct the Porsche initial public offering (IPO) in the fourth quarter of 2022, though that may change if the conflict in Ukraine drags on, Porsche SE’s finance chief said. “We cannot rule out, if the conflict lasts a longer time, that this could have potential implications on the listing,” Johannes Lattwein told a news conference, without elaborating on how it would affect plans. No final decision has been made on the proposed IPO, the company said. A framework agreement for the listing proposed by Volkswagen in February includes selling 25 percent plus 1 ordinary share in the carmaker to Porsche SE as well as listing up to 25 percent of Porsche AG’s preferred stock. …