Guy Wyser-Pratte, the Franco-American activist investor, has bought 5% of a trouble-hit Swiss private equity company, as the resurgence of activists across the continent continues. Also this week, Elliott Advisers has demanded a revamp of strategy at UK travel company National Express.

Wyser-Pratte has teamed up with a partner this time; Mantra Investissement, in order to purchase just over 5% of Private Equity Holding, a Swiss investment company that commits money to private equity funds.