The deal was for longstanding private equity client Sagard, one of many Ashurst clients who are expected to continue instructing him at Latham.
Forschbach advised Sagard on its joint acquisition with the Faiveley Group of Sab Wabco, a company that produces brake systems for the railway industry.
Forschbach began work on the deal before he left Ashurst, supported by associate Denis Criton, who also made the leap to Latham.
The Faiveley Group was advised by Weil Gotshal & Manges’ David Aknin.
At a total value of €516m (£359m), the deal is one of the largest private equity transactions completed in Paris this year, and unusually it was not structured as a leveraged buyout.
“This was providing basic capital to make an acquisition, which is not a standard private equity transaction these days,” said Forschbach.
The US seller of Sab Wabco was advised by Simpson Thacher & Bartlett London corporate partner Michael Wolfson. The deal also involved elements of Swedish law.