Permira, one of Europe’s biggest private equity groups, on Wednesday promised to return “a wall of cash” to investors by floating or selling a substantial number of its portfolio companies, adding to growing optimism among buy-out bosses.

The company’s defiant message follows a tough year for the group, which wrote down its portfolio by 36 per cent and shrank its latest fund from €11.1bn to €9.6bn due to difficulties at its biggest investor, SVG Capital.