Zurich-based worldwide aviation service company Jet Aviation is being acquired by Permira, a European-headquartered private-equity group. With a formal closing expected in late September, the sale will end uncertainty over the fate of the Hirschmann-family-controlled enterprise, which had been informally in play since the family put it on the market in early 2002. The Hirschmanns eventually took it off the market later that year after family members and potential buyers, including Permira, could not come to terms. Activity on the current sale started in the second quarter of this year when unsolicited bids to acquire Jet Aviation came in from Permira and others, including The Carlyle Group, a U.S. private-equity firm whose subsidiaries include Garrett Aviation Services, Piedmont Hawthorne Aviation and Associated Air Center. Today’s announcement said Permira would “acquire the majority shareholding of Hirschmann/Jet Aviation Group.” Although details of the agreement were not disclosed in the announcement, sources close to the transaction believe the shareholding is more than 75 percent and valued at more than 800 million Swiss francs ($640+ million). This would place the total value of Jet Aviation at more than $700 million. It is also believed that the decision to sell to Permira hinged on “cultural issues,” that in the end the Hirschmanns preferred a European buyer.